The part that blows my mind is that according to this article, the idea that we evolved in a straight line was an attempt at fighting nazi propaganda about inferior races. Before ww2, the scientific consensus was that we evolved in a branching species rich manner, same as any other animal.
By 1963 it was again okay to talk about multiple hominid species, so the scientific consensus started moving back in that direction.
I find this fascinating because I never realized science could be so political.
More interestingly still, when the author talks about species being mis-identified as homo sapiens despite stark morphological differences and that they probably represent an extinct close relative, that gave me a funny gut feeling. Felt like dangerous territory to talk about …
The history of taboo thought in science is indeed fascinating.
What seems sort of funny is that now that the existence for potential taboo censoring has been recognized, in recent decades there are several charlatans, conspiracy-mongers, or other ideologues who paint themselves as subject to scientific taboo despite "being accurate" in their own minds. The pendulum has swung towards over-acceptance of claims.
> Before ww2, the scientific consensus was that we evolved in a branching species rich manner, same as any other animal.
This was a time referred to as the "nadir of race relations" in the US, and if you read the output about humans as a species from that period, you'd be a lot less impressed. It's all out of copyright and a lot is available online. It's not what most of us would look at as science, now. It's more like mythmaking.
Also, take a look at the history of eugenics, which was seen in the years before World War II as a legitimate and noble scientific goal - to improve the human species by the application of science and engineering, no more immoral than breeding hardy tomatoes or fast horses. Many countries that joined the war on the side of the Allies had significant scientific, governmental, and public support for eugenics (the US and the UK had a Eugenics Society, Canada had provincial Eugenics Boards in Alberta and British Columbia, etc.). Neutral Sweden had an active eugenic sterilization program.
So, the "scientific consensus" of that era involved a number of scientists from many countries who agreed with policies and goals that, in retrospect, we now see as not only politically partisan but also specifically aligned with Nazi political ends.
Yes, a lot of scientists believed in hateful pseudoscience like scientific racism, eugenics and phrenology.
Your argument is a very common one but very flawed. Antisemitism, ultranationalism and eugenics aren't bad because the Nazis did it. It's exactly the other way round!
Eugenics are just as flawed and criminal when a Swedish doctor or a British politician advocate for it.
I think you're misunderstanding my point - I'm saying that eugenics was bad at the time, even before the Nazis implemented it at horrifying scale, but the scientific consensus of the time was that eugenics was a perfectly reasonable thing to work on, and therefore we should not trust the scientific consensus of the time.
If the scientists of that era said that certain humans were an inferior species to Homo sapiens, and the scientists after World War II said that's not true, we shouldn't assume that the pre-war view was pure untainted science and the post-war one was the result of overcorrecting for political/moral reasons - we should consider the possibility that the pre-war scientific consensus was tainted by political/moral views that we now rightly reject.
> This was a time referred to as the "nadir of race relations" in the US,
Its incredible how little people know about the period in American history between the end of Reconstruction and the start of WWII beyond just: "WWI", "Market Crash", "Great Depression".
Following one theme: Nadir of race relations, Red Summer of 1919, and Great Migration (one of the largest movements of people in history).
It makes it so much more difficult to have an objective discussion about the past simply because people are unaware of it, or simply understand it at a very high / hand-wavy level. "Some bad stuff happened then eventually it stopped."
Frankly I think we're quite lucky we're not a more diverse species. There's no biological reason a human subspecies couldn't have gotten isolated in a valley somewhere and ended up being fifty IQ points smarter or dumber than the rest of humanity. Same goes for our sexes being identically intellectually capable. Would the principle of egalitarianism have ever emerged in such a world?
> There's no biological reason a human subspecies couldn't have gotten isolated in a valley somewhere and ended up being fifty IQ points smarter or dumber than the rest of humanity. Same goes for our sexes being identically intellectually capable. Would the principle of egalitarianism have ever emerged in such a world?
I want to say yes, because how are you even distinguishing that world from this one? There exist humans who are fifty IQ points smarter or dumber than other humans who also exist.
The batshit crazy idea is that these differences are caused by or intrinsically bound with skin color.
> All or most of the major tests commonly used to measure intelligence have been constructed so that there are no overall score differences between males and females.
We believe in egalitarianism, therefore IQ tests that show a sex difference are wrong, therefore we use IQ tests that show no sex difference.
Now, if there are biological differences between the sexes, they could not only go either way, they could go both ways. It's possible that on average women are better at X and men are better at Y, so you could really design a test to show whatever result you want.
It's also obviously the case that no matter what the averages are, the world's highest-scoring male will almost certainly have a better score than the world's lowest-scoring female and vice versa. So arguments of the form "women can't do X" are stupid even if you can find a statistically significant difference in the averages using some metric. Because most people are not exactly average.
Discrimination is the assumption that all members of a group are the same.
There exist humans who are fifty IQ points smarter or dumber than other humans who also exist.
Sure but they're not all in the same ethnic group. What if a populous group had the peak of their intellectual curve far down the range? If, say, Gauls/French people were almost entirely simpletons equivalent to someone with Down Syndrome? Would they be enslaved and turned into a worldwide servant class? Every other group that were thought of as being inferior can be demonstrably equal to their oppressors but I think a world in which they weren't could be very different.
> What if a populous group had the peak of their intellectual curve far down the range?
It takes a long time, an evolutionary timescale for that sort of difference to emerge. There’s an argument that the reason that modern humans are so homogeneous is because we wiped out all competition long before we had recorded history or civilisation.
The thing is, when humans conquer a rival group, we tend to rape the survivors. That kind of ensures genetic mixing, so this kind large discrepancy in innate ability couldn't really appear.
We wouldn’t want a world where IQ fetishists were to be even more discriminatory against people with lower IQs. (Or supposedly lower IQs.) It’s bad enough as things currently stand.
There's also no biological reason 8 billion individual hominids evolved under different conditions and upbringing and nutrition should share the same intellectual capacity, any more than all 8 billion would be equally good sprinters or have the same skin tone or oxygen capacity.
The brain is just another blob of flesh, and what we understand of its capacities suggest it's at least partially inheritable. You'd have to ignore a lot of evidence to believe that all humans are intellectually equal. If there is variation and there is mutation and there are different pockets of populations, there are going to be evolutionary differences between them. Then in terms of sexual selection, we'd have to believe that intelligence as a criterion for mate selection is equally important across cultures, and also impacts offspring fitness the same across all cultures and environments -- vs, say, disease or sun resistance in the tropics. Otherwise, differences would naturally arise over time.
The tricky part is coming up a way to define, much less measure, "intellectual capacity" across different cultures and ways of knowing. IQ tests are pretty biased and arguably a useless measure of evolutionary fitness in many human cultures. Even if you could create the perfect cross-cultural IQ definition and test, administering and collecting such a thing would be nearly impossible in a world where many countries don't even have proper birth records or thorough population censuses (even a basic count, without in-depth testing).
We already know that, within the upper and lower bounds, there can be great variations of "intelligence" WITHIN populations group, as well as smaller differences between them. But we lack the methodology and cultural transparency to be able to accurately measure whether the cross-cultural error bars fall within the intracultural ones. That's not for lack of trying, mind you... many careers have either risen to infamy or else have been destroyed for daring to suggest such things.
In other words, it's not that all humans are equal, it's that we're SO diverse it's hard to group us into neat little groups, whether by race, ancestry, skin color, intelligence, or any other genetic factor. Because the underlying genes themselves don't work that way. They're always changing and competing.
The principles of egalitarianism are a cultural ideal (not shared by much of the world, mind you), not necessarily scientific observations. The scientific input to the ideal, if anything, is not that "the are no differences between groups" but "there are so many differences that these groupings don't really make sense; there are a million other equally valid groupings".
The only reason why there are no other hominids on this planet is because homo sapiens were the most violent of the subspecies. It's in our blood to enslave any opposition or rivals if possibel. When not, we exterminate them. We do the same within our own species too.
> I find this fascinating because I never realized science could be so political.
Surely we already know that there was research (whatever its quality or rigor) back pre-WWII that was supposed to defend racist theories. And that’s political. So I don’t understand why we would be surprised that there was a (political) backlash once millions ended up dying in part because of that kind of research.
Taxonomy is a wild world, exactly because species are human inventions. Taxonomists can generally be classified as 'joiners' (who advocate for fewer species) and 'splitters' (who advocate finer divisions). The linked article is written by a splitter. "Can't produce human speech sounds" seems like a good indication that a split in human taxonomy is worthwhile, though.
They are, in the same sense as “rain”, “fog”, “snow”, or “sunny weather” are human concepts, and not natural low. After all, these are invented by humans, blurry on the edges, and sometimes overlap.
It breaks down with edge cases. There are a few documented "ring species" such as a diverse land-based amphibian around a lake. At all points the adjacent neighbours can mate, but if you take examples from the far side of the lake, they cannot. One species? Two? Infinite?
I think it was Richard Dawkins who extended this idea through time. We could mate (sorry) with our immediate ancestors, who could with theirs, etc. and in fact there's a continual chain like that all the way to any other mammal. When did we stop being our ancestral species and become H. Sapiens? No clear line.
A ring species is an example of a species complex, and subpopulations with different but not mutually exclusive breeding compatibility are known as microspecies. If populations with distinct morphological features are isolated in space or time but could still interbreed with eachother if they were to be brought into contact, they are subspecies.
This is really just an instance of Sorites paradox. But the inability to draw a precise line between two (or more) states does not mean there aren't two (or more) states.
If you eat two pancakes with butter between like a sandwich, it is a variant of butter sandwich. If you cut up your PB&J such that you're only eating pieces of bread with some spread on them, that is not a sandwich. The bread must act as a container for the contents during consumption, regardless of ingredients.
More generally, the key delimiter for sandwiches is the aspect ratio of the individual items contained by the bread. For something to be a sandwich, all of the major items inside must have one dimension which is substantially smaller than the other two. Sliced meats, bacon strips, cheese slices, sliced vegetables, lettuce leafs, spreads, patties, etc are all valid. Thinly spread peanut butter and jelly between bread is a sandwich, but a bread bowl with a pool of jelly and peanut butter where the depth is comparable to the radius would not be a PB&J sandwich. Flat cheese slice between bread is a sandwich, mozzarella sticks are not sandwiches. Hot dogs are by default not a sandwich, but if you cut the hot dog into thin strips it becomes a sandwich. An oreo is a sandwich but a quadruple stuffed oreo is not. The only commonly accepted sandwich which this definition claims to be a pseudosandwich is the meatball sub.
You're carving out a definition to fit intuitive inferences gleaned by observing instances of "sandwich" and "not-sanwich" labeled by influential people in your life who had no objective reasons for constructing and perpetuating those categories in the first place.
I agree it would have been a lot easier if we precisely defined the sandwich before foods were invented so we'd know which category to place them in ahead of time, but alas barring the invention of time travel we have to deal with our forefathers' mistakes.
But what about the named club sandwich, which 1) has a width to height ratio so unfavorable it needs toothpicks to hold it together, and 2) often has more bread than ingredients (at sub-par establishments), but sometimes far more ingredients than bread (leveraging the toothpicks).
Regardless of these facts and it not meeting your criteria, it is still both in common usage and by explicit name a sandwich!
It's not the thickness of the sandwich, it's the thickness of the individual things in the sandwich. Everything in a club sandwich is flat, there's just a lot of stuff.
(Sorry, can't resist keeping this going, this is some good discussion).
It's true I guess that the aspect ratio for most ingredients is 'flat', but many are thicker than the bread, and the whole sandwich is 'sideways' aspect ratio wise.
This definition includes open faced sandwiches so long as their contents have the appropriate aspect ratio and you hold them via the bread. If you needed two pieces of bread to make a sandwich then that would rule out everything served on a roll. Pizza is an open faced true sandwich, pancakes are not.
That said, just because something has a word in the name doesn't mean it's a subset of that category. Strawberries aren't berries, english muffins aren't muffins, prairie oysters aren't oysters, black pudding isn't pudding, etc.
The aspect ratio rule fails for a bagel-with-cream-cheese from a NY food cart, clearly a sandwich, which has a square of cream cheese which is as large as the bagel in 2 of 3 dimensions.
I don't really get how your prescriptive rule means open faced sandwiches somehow "contain" their contents. Then again, since I don't believe in being prescriptive, I don't really care to think hard enough about the contortions of logic required by your approach.
But it has 1 dimension, it's thickness, which is substantially smaller. You don't have a cube of cream cheese, you have a thin square. Thus it satisfies the aspect ratio rule, which, again, says there is one substantially smaller dimension than the other two.
A container is something which contains. If you can manipulate something by the bread part and the contents stay put, they are contained. While the aspect ratio rule may be legitimately controversial, if you don't restrict your definition of sandwich at least to stuff contained by bread then what isn't a sandwich?
The whole point of this exercise is to taxonomically categorize foods as being sandwiches or not sandwiches, how would you do that without being prescriptive?
There are far too many edge cases (e.g. ring species), but it's also not practical. How are you going to decide whether two individuals can't reproduce together, or choose not to? What if all you have are some dead specimens?
It's mostly based on DNA analysis these days, I think.
Even if we limited ourselves to the Homo genus, the rule does not work well.
Based on the admixtures of Neanderthal and Denisovan DNA in modern humans, we once had a lot of sex with those other humans (and they with us), resulting in fertile offspring, but the differences between us and them are pretty meaningful and probably worthy of not considering us and them just subspecies of the same species.
For example, Neanderthals probably could not vocalize in the same way that we do; and being capable of speaking is quite an important distinction. They had very different anatomy, including that of important joints (shoulders).
Theoretically that wouldn't be a killer issue, since fertile mules are extremely rare, so you could refine the definition to say "is very very likely to produce fertile offspring" (while horses and donkeys breeding is not).
The bigger problem are things that have massive morphological differences but can still successfully interbreed, such as dogs, coyotes and wolves. They produce fertile hybrids and there is good evidence that this occasionally happens in the wild, but nevertheless it is rare and they have clear, stable morphological distinctions, even in areas where they overlap.
Even worse, that definition is entirely useless for paleontology, as it is impossible to know if two individuals species could even interbreed, nevermind knowing if their offspring would be fertile. Even modern genetic evidence (which is extremely rare for fossils anyway) is very open to interpretation on the matter of potential interbreeding ("Neanderthal" genes in modern humans could more or less as easily be common genes older than both H. Sapiens and Neanderthals - we have far too little evidence to be sure, and no chance of genetic material from an older ancestor).
If neanderthal or denisovan genes were ancestral, you would be able to find them broadly in African genomes and some of them wouldn't carry adaptations to environments not found in Africa. Instead they reinforce (and inform) our understanding of early human populations out of Africa.
How do you actually test that as a working ecologist, though? Given two geographically and somewhat morphologically district warblers (for example) you would need to convince two of them to breed (after capturing at least one) and then check viability of an offspring. It's not terribly practical...
Or, in this case with ancient human remains, there's no way to check viability when all subjects have been dead for a hundred thousand years.
> And there are circular arguments: DNA is identified as, say, Neanderthal because the fossil was identified as such, and then it is used to identify other fossils as Neanderthal, even if they don’t look Neanderthal-like.
This is the opposite of a circular argument, this is the foundation of inductive reasoning. A = B and B = C thus A = C. If something has unambiguous neanderthal DNA but doesn't look neanderthal-like, then your idea of what is neanderthal-like is discredited.
The issue is that humans share ~99% of their DNA with chimpanzees. Pick any of that, say "this is chimpanzee DNA," and you're now identifying billions of humans as chimpanzees (or vice versa).
And 60% of our DNA is shared with a banana, but that's not the dna used to classify species. The overwhelming majority of both our and chimps DNA comes from our common ancestor, and all of that is neither human nor chimp DNA. But there are specific genes which Chimps evolved after our lineages diverged, and any animal containing those genes must be in the chimp lineage.
In the case of hominid interbreeding, we can see genes that are common in neanderthals appearing in non-african modern humans. Had these genes existed in our common ancestor, they would be present in african populations as well. The opposite being the case, the only way for those genes to get there is if only some people descend from neanderthals, which in turn requires successful interbreeding.
Suppose humans migrate to Europe from Africa, then have some local divergence from their ancestors. Then those humans interbreed with neanderthals, so that those divergent genes spread within the neanderthal population as well.
Putting aside the question of whether the existence of interbreeding makes neanderthals not a separate species, it's going to be difficult to tell where those genes originated.
Suppose the first person to have those genes was a human who bred with both humans and neanderthals, but it so happens we have fossils of some of the earliest neanderthals with those genes and not the earliest humans with them.
Then you could have the result that some "neanderthals" descended from humans but not vice versa, and be unable to distinguish that from the other way around.
This would be an issue if you were naively looking at a single mutation in a single gene in a single individual without context, but the problem disappears when looking at large numbers of whole genes in many individuals with fossil evidence for context. You can see more basal forms of genes, combinations of genes which get passed on together, biological clocks indicating when a mutation occurred, and geographic information indicating where it originated. If a gene variant exists for hundreds of thousands of years in one population, and then a nearly identical variant suddenly starts showing up in another population, it's safe to assume that some hanky panky took place.
We do indeed find neanderthals who descend from humans, interbreeding went both ways. For example we can see that around 100,000 years ago, the neanderthals' y chromosomes were almost completely replaced with a modern human y chromosome whereas even as late as 38,000 years ago there were still neanderthals with purely neanderthal mitochondrial DNA.
This is also the point where the author lost me. But it was because of the dismissal of the molecular evidence. That molecular evidence is very compelling and has vastly improved our knowledge of early homo. Disagreeing with what the molecular evidence means would be valid, but dismissal is a sign of ignorance.
It is even more surprising that people dismiss genetics in a age when national borders are closed based on such analyses of COVID genomes. The nextstrain resource is a great way to get an intuitive grasp of what genetics gives us. https://nextstrain.org/ncov/gisaid/global
The core problem of taxonomic classification of species is that they're semi-arbitrary, constantly-drifting centroids of similarity, not static, walled-off groups with definitive boundaries.
For those who aren't scientists, we are sometimes referred to as H. sapiens sapiens.
Neanderthals / Neandertals are sometimes grouped as a subspecies of H. sapiens as H. sapiens neanderthalensis.
The problem of classification is deeply philosophical. The core problem is that the taxonomic classification of anything is arbitrary, proven only by consensus.
I've had a series of conversations elsewhere over the past several months on the question. My own view being that classifications are based on usefulness to the classifiers, and we have terms for things which we both 1) experience (there's much of the Universe we've yet failed to classify) and 2) based on our own interactions with those things.
Ideas are interfaces. And interfaces provide utility.
The very notion of "biological species" is based on the underlying notion of philosophical species, that specific classifications. Evolution turned this on its head by noting that species evolve (that is, change), over time. There is no such thing as an absolute species in the earlier philosophical sense.
So the question becomes "where is it useful to define boundaries between species?", with various arbitrary boundaries proposed. The question isn't of their arbitraryness, but of their utility.
And those definitions are ultimately a relationship between us and the universe we're attempting to define.
You can drag in Wittgenstein and a whole bunch else. Knowing some of the philosophical background is useful, less so because a particular view is right, but more because virtually any argument or viewpoint proposed has been offered before, and many of the strengths and weaknesses discussed. Usually to great length.
If I understand you correctly, biological taxonomy, a thing we've had for hundreds of years, and over which huge intellectual battles have been fought, is basically all about making scientists happy, and has little to do with the actual reality of a vast population of living things that is constantly changing over time.
Because, if I did understand you correctly, I completely agree with that.
Not entirely, though there's a fair element of that.
With gene sequencing and techniques such as molecular clocks we can determine evolutionary trees and the approximate time between mutations. This gives us a fairly clear understanding of what current species are placed where on the evolutionary tree --- where you draw the boundaries still has some ambiguity, but it's usually possible to at least say which of two specific samples is closer to or further from a third.
We've also realised that genetic inheritance and transfer is not strictly along descendent lineages --- there's swapping of genetic material, espeically between living organisms and viruses, as well as amongst complex organisms and bacteria. Your mitochondria --- common to nearly all eukaruyotes --- is itself an entirely distinct organism which has become entirely symbiotic with you.
So there's nearer and further, and indirect inheritance. But there remains a great deal of cases --- remember, 99.9% of all life forms on Earth have gone extinct --- where we simply do not know. Or where knowledge isn't sufficient to make a clear or unambiguous distinction or classification.
Jainism has the concept of Anekantavada, "many-sidedness", exemplified in the fable of the blind men and the elephant. It's useful to recognise that our perceptions are arbitrary --- they're dependent on both the particular subset of reality we're observing, as well as the limited channels through which we're making that observation, and the conceptual frames by which we organise it. That said, many sidedness is not any sidedness --- all interpretations are not equivalently valid. That's the gist of a utility model of epistemology: usefulness is context-dependent, but also exists on a spectrum, from high usefulness (greater truth value) to low (likewise).
Arbitrary is not indifferent.
Mind as is usually the case I'm speaking of an area in which I have largely lay knowledge, though I think I'm not going too badly astray.
I also read it as utility an usefulness in a more practical sense. It's useful to differentiate between horses and donkeys, so we call them different species.
Well, we have names for that: "horse" and "donkey".
I get that having formal names is useful, and basing those names on ancestral characteristics seems sensible. But it doesn't seem to take into account that this is a moving target: everything is evolving, and populations are not going to stay the same over time. Trying to classify every living thing into neat categories is like herding a million very slow cats. Especially with palaeontology, where the timespans are large enough for evolution to really matter.
Other cases might be the various organisms we classify as "trees" or "fish" or "crabs", which are valid from a functional or role-based sense, but which aren't robust when considered strictly based on genetic evolution. That is, there have been multiple convertent evolutionary paths which have arrived at similar forms, roles, and niches, despite having hearer relatives or ancestors which don't fall into that category.
I like to half-jokingly claim that people who use the internet are a different species from people that don’t use the internet, since the two groups don’t interbreed.
While you are of course right, and much terminology is endlessly challengeable, we can also drift too far in this direction and end up denying that words mean anything. I do find words useful when there is consensus on their meaning, and I think it is still valid to attempt to define classifications even where they must inevitably be imperfect.
Well, they are tripping on their own imprecise definitions.
Using the most prevalent definition of species, the one listed on Wikipedia, we don't have "too many species lumped together into Homo Sapiens", we actually have too few. We know all or almost all "species" since and including Homo Erectus were able capable of interbreeding, meaning they were actually single species.
The trouble is they are trying to use definition that has been developed on observation of the current state that is not suitable for classifying evolving organisms over long periods of time.
That might not have been a huge problem when discussing other animals, but for some reason we pay much closer attention to precision of resolving our own parentage and that is when the definition falls short of being able to serve the need.
> We know all or almost all "species" since and including Homo Erectus were able capable of interbreeding, meaning they were actually single species.
While this is what we were taught in grade school, actual biologists don’t use this children’s definition anymore than actual quantum physicists say atoms are like little solar systems.
There are plenty of separate species that are physically capable of producing fertile hybrid offspring. Dogs and wolves and polar and grizzly bears are a couple obvious examples. Also plenty of species don’t reproduce sexually, so defining species in terms of sexual compatibility isn’t even well defined.
> actual biologists don’t use this children’s definition anymore
Can you link me to the definition biologists use? I googled for a minute and didn't get very far.
Wikipedia (https://en.wikipedia.org/wiki/Species): "A species is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction."
Yes and I think we're stuck with what's already happening: modifications to existing classifications by genetic discoveries as they occur. There's no good way to please everyone, have a trillion special cases, or throw it all away because it's imperfect.
IMO it's that "species" is a term coined by older, less-informed biologists who didn't yet understand all the nuances of genetics, and created a taxonomic system based, erroneously, on superficial differences in appearance. It's like how old scientists believed in "ether" to describe the mysteries of space and "humor" to describe the mysteries of the body. Species is what old scientists used to describe the mysteries of genetics.
Older, less-informed biologists also gave us scientific racism.
Polar bears and Asiatic black bears live in different places and have different appearances and behaviors. They called those different species.
Norwegian humans and Chinese humans live in different places and have different appearances and behaviors. They called those different races.
If we're gonna go down that route, probably our genetics gave us racism. Many species are "racist" towards other populations that they might've otherwise bred with. Extant primates also engage in what would be called genocide if performed by humans. All just because the other group lived in some other place and might've looked/smelled/talked a bit different. Nature is cruel and unforgiving and does not give two damns about egalitarianism.
Equality is a human cultural construct, a social contract that attempts to minimize in-group violence. It is itself a cultural evolution, a relatively recent one in the West, longer-lived than that in other cultures, but altogether very limited and mostly only applied to some convenient in-group du jour, not humans around the world and certainly not to hominids at large.
Equality has no real evolutionary basis. Evolution depends on inequality in the face of selection pressures. May fit individuals breed, may adaptable populations persist, and may the sexiest genome win.
Scientific racism failed both because of changing social norms and because taxonomy-by-appearance was doomed to fail upon closer inspection, not because humans are inherently equal... we're anything but, and those "self-evident truths" are believed by no one in particular, not even grade school kids. It's ironic that the nation who says that on one hand has, on the other hand, produced one of the most unequal societies in human history.
If society is ever to actually become egalitarian, it must be because we -- by social contract or force of mythology -- place equal value on each individual, not because our genetics are the same. We're not clones and we're all better and worse at some things, and most of us are completely mediocre at everything except, maybe, being an adaptable hairless ape between ice ages in the temperate zones of a wet rock floating around a star.
In other words, we can't morphologically evolve our way out of racism, but perhaps -- someday, if we survive these next few decades -- we can culturally evolve more egalitarianism. Genomes aren't the only unit of information reproduction anymore. We can only hope culture will succeed where nature failed.
There isn’t one. “Species” is an abstraction, vague when you look too closely, and increasingly meaningless when you move from animals to plants to fungi to bacteria and archaea.
There’s just no way to decisively say exactly when two closely related organisms transition from one species to two.
You will find debate and varying methods but in the end for the professional scientist, it’s mostly an unimportant question for most because it’s obviously just vague and never possible to be perfect, and you have to ask “what’s the point?” of the really fine grained labeling which seems to only be done for the purpose of labeling.
There isn’t a correct and concise definition, any more than than there is a correct and concise definition of good art, good code, mathematical proof, or sandwiches. https://plato.stanford.edu/entries/species/
Even the term planet has recently given us trouble. There we’ve adopted a definition, it’s just not fully agreed upon.
> A mathematical proof is an inferential argument for a mathematical statement, showing that the stated assumptions logically guarantee the conclusion.
Unlike all the other sciences, mathematics is abstract enough to allow for things being fundamentally simple and true.
As a mathematical object, a proof is a series of derivations from axioms to a conclusion. That is well defined in various systems, can be studied as a branch of mathematics.
In fact, most mathematics isn't done this way (though there's interesting work in the Lean community). Mathematical proof as it is actually done is far messier. Here's the paper that first came to mind (Probabilistic Proofs and Transferability, by Kenny Easwaran), though I'm sure there is a more canonical source: https://ucfc6eb8f695030deb8332de441a.dl.dropboxusercontent.c...
P.S. You're free to adopt a way of speaking in which you say the majority of graduate mathematics textbooks do not involve any proofs, but I think that's a revision of the term.
I think it's fair to say that the state of the art of proofs is the equational form. Recorde revolutionized mathematical writing with a couple parallel line segments. Generalizing that to proofs using the equivalence, consequence, and implication is an equally (hoho) great leap forward.
That Wikipedia article does cite other ways of defining species, just after your quote.
The bottom line is that there is no one correct and concise definition.
It's also obvious that the fertile offspring definition is not sufficient of you look at plants (pomelos, mandarins and citrons are rather obviously different species, but they are interfertile and most modern citrus species are their hybrids) or even more obviously, at bacteria or yeasts that don't even reproduce sexually.
Wolves are canis lupus, while dogs are canis familiaris (and coyotes are canis latrans). All are capable of interbreeding and producing non-sterile offspring.
Philogenetic taxonomies may suffer from this, yes. Ontological classification is a different ball game. Any "rational animal" in the universe qualifies as "human".
I'm usually the first person to complain about political correctness. I've just always considered humanity to be at the genus level, not the species level.
I'd really, really, like to see a statistical comparison of the differences between and within (fossil) species.
"And the more specimens I study, the more I realize that most of the species designations don’t make sense. If hominin fossils were treated the same way as nonhuman primates, specimens currently lumped into the same group would be allocated to different ones."
Is this because the differences between purported groups is much greater than the differences within groups? Or because there's significant incentives to split groups in order to name more species/families/orders/etc?
The "traditional", extremely simplistic, definition of "species" is a group of critters who do not (normally) (fertilely) interbreed with another group (in the wild). Where there is evidence, Neanderthals and Denisovans, H. sapiens seems to have interbred rather frequently.
> Or because there's significant incentives to split groups in order to name more species/families/orders/etc?
You can ask yourself why such an incentive wouldn't exist for finding new human species etc. The interesting part here is that humans are treated differently, not whether one is better than the other.
According to the article, before the 1940s, it did. Judging by the list of species in the image with spell-check underlines, anyway. Something weird happened in the 1940s.
To expand on this, a lot of intellectual energy was spent on expanding and properly defining what was meant by "Human" in order to preclude any perverse interpretations, such as what the nazis did, and to shut down a lot of eugenics nonsense.
Reading natural sciences and eugenics books written prior to the 40s is fascinating - there's all sorts of casual racism and talk of different cultures of people as if they were completely different species. Global communications improved after the 40s, and it became progressively more difficult to pretend to be a scholar or intellectual in public if you had racist or supremacist biases. The current state of liberal acceptance and human rights in the modern world is part of a trend that was an incredibly radical departure from almost all human culture prior to wwii.
Criteria for being classified as human are diverse, most of the criteria we use for classifying living people (some of which are actively being used to commit genocide) cannot be applied to our ancestral lineages, we give our genes too much credit relative to our memes, and cladists will use whatever evidence they can find to support their cladism. If the splitters in the lumper splitter debate are using splitting as an excuse to murder and disenfranchise people then it is hard in good conscience to openly articulate the truth and ethically is probably better to attempt to slow the splitters' efforts by confusing the whole field with alternate hypotheses.
On the whole lineage does not imply capability, skeletal anatomy is not predict cultural level, etc. but because the great chain of being continues to drag our civilization down to its lowest basest form we belittle anything and everything that looks even slightly different than us. The fact that the null hypothesis in life sciences is that other species do not feel pain, do not have emotions, do not have cognitive process, etc. is derived from the abhorrent idea that only human beings have souls, or that the abhramic god gave man dominion over the animals. Is it a surprise then that some scientists have fooled the bigots by classifying everything as human? They know that by some criteria the lineages are sufficiently different to be classified as such, but there is no reason to give bigots ammunition for public policy.
That's a bit of a human trait, categorizing things. It's not like evolution decides to suddenly have a new species, it's by definition liquid, generation for generation.
The fact that there are many more clearly defined species is because "fitness" (which sometimes includes very random events happening) results in many "species" (or sub-species or variants or groups of mutants) to die out eventually and one lucky/fit group to survive.
With homo sapiens, like with many other only recently established species that didn't really happen. Or well, it did and that's why we have that taxonomy problem. But you can draw all sorts of lines. Of course the whole race topic comes in there too and what about people who are able to drink milk after a certain age and those who don't.
Species are sometimes distinct by very minor traits like that and not always by being able to have offspring.
So decisions are either made by people who establish species or by a majority of scientists agreeing, so more or less through a political rather than a scientific process. Of course that means it comes to a lot of bike shedding on these topics.
It's more a discussion about what the definition of the word species is than anything else.
1. speciation (as I understand it) has a clear definition: if two populations can mate, then they're the same species. I don't think preferences come into this - for lots of reasons (the vast number of possible interactions between populations, consent isn't required to produce offspring, etc). Saying "I don't think these people would fancy each other" isn't enough to define a new species.
2. the clear differences between specimens recovered does not reflect any clear difference between populations over time. The population of homo-ish living beings over the last 100,000 years is enormous, and we've recovered a tiny, miniscule, fraction of that. Classifying specimens is fine, but we shouldn't make the mistake of thinking that those specimens represent actual populations of humans. The sample size is too small to draw any meaningful conclusions.
I think the effort to minimise the differences between early humans is admirable, and should be continued. We have a tiny, farcically small sample size of evidence to base any conjectures about early humans on. Being inclusive about Homo Sapiens because it stops nazis being dicks about race is a good thing.
For 1. No, it is a lot more complicated than that. For instance, Dogs, Wolves, and Coyotes can all interbreed with each other. But even if you treat all dogs as one species, they can't actually all interbreed with eachother without human intervention due to size differences. Then there are ring species, which can breed with two separate species that cannot breed with each other. That isn't even getting into species that can asexually reproduce.
That concept (populations which can share genes) is for species which have sexual reproduction. For populations which require special conditions, you can talk about subspecies.
But not for the rest of lifeforms. Bacteria reproduce by cloning themselves and they can share genes laterally (between adults). And viruses are really more similar to computer viruses with intended replication errors than a lifeform.
> I think the effort to minimise the differences between early humans is admirable, and should be continued. We have a tiny, farcically small sample size of evidence to base any conjectures about early humans on. Being inclusive about Homo Sapiens because it stops nazis being dicks about race is a good thing.
Science should not be corrupted by the goal of countering human irrationality. It's no use: racists will use "science" to rationalize their positions whether or not mainstream science agrees. And it's harmful: the more science deviates from the pursuit of truth, the less we all can trust it.
The ability to mate is just one among numerous phenotypical characteristics. Whether to elevate it to anything special of course depends on the fuzzy boundary of whether or how much it is actioned on.
> if two populations can mate, then they're the same species
Wouldn't that mean homo sapiens and neanderthals are the same species, given that many people have neanderthal genes and interbreeding is even a hypothesis for the extinction of the neanderthals?
1. Common counter-example: Horses and donkeys are considered separate species. They can produce offspring. There have been rare cases of that offspring being fertile. Not so clear.
Traditionally, two members of a genus (but of different species) make infertile offspring.
Two members of a species make fertile offspring.
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This isn't a "perfect" definition, but the delineation is clear in most cases. In your case, a horse and a donkey make infertile offspring (aka: a mule), and are therefore different species but the same genus.
Nothing is effective enough for those extremes. But for the rest of society, specially those during school years, this is enlightening and hopefully enough to push agaisnt our inherent racism.
Interesting. A deep seated cognitive flaw of a positively-directed evolution (more evolved vs less evolved) places us in the situation where we are forced to characterize all humans and predecessors that are close enough into Homo sapiens.
But that is only because we have this innate cognitive error.
In some sense, intelligence past a certain point should be sufficient to classify as “one of us” but such trans-species sentiment is generally limited to those who believe memetic reproduction is somewhat more important than genetic reproduction.
The one thing the article does not help me understand is the purpose of the classification. The utility of models to me is in the ability to make falsifiable predictions about the real world. Is it perhaps the history of our species and the way speciation works that is being contributed to? That seems reasonable and makes the taxonomic classification have some utility. But perhaps categorization is not a useful tool here, and tagging is superior, i.e. “neanderthal-like in feeding habits” and “sapiens-sapiens-like in communication habits” and so on.
But we can and do. So this question is moot. It becomes important the further back in time you go, but it’s not like we don’t have Neanderthal DNA sequences.
> And there are circular arguments: DNA is identified as, say, Neanderthal because the fossil was identified as such, and then it is used to identify other fossils as Neanderthal, even if they don’t look Neanderthal-like.
> While certain similarities between our DNA and Neanderthal DNA have been interpreted as evidence of the two species interbreeding, these similarities could just be run-of-the-mill features of the genome, common to many species.
These and other arguments by the author to try and dismiss DNA evidence seems really suspect. The "circular reasoning" argument doesn't even make any sense. Neither does the scientists being too stupid to understand that DNA overlap between Neanderthals and humans is meaningless.
As a non expert, this makes me have doubts about the veracity of any of these arguments made in this essay
There's always been a push and pull between the splitters and the lumpers. Discovering a new species can seem more exciting than finding another member of an existing study. But the concept of a species (genera, etc.) is very slippery anyway; sometimes its said that inability to breed viable offspring is a necessary condition, but we have examples of that happening ... without subsequent revision of the taxonomy. Life (and the physical world), slips past the edges of our ontologies all the time (one reason that I laugh when people justify the object model in programming in terms of them somehow mapping onto real world objects.
> People sometimes forget to ask the question: If humans and Neanderthals actually crossed paths as often as molecular anthropologists claim—which is not supported by archaeological or paleontological evidence—would they have recognized each other as potential mates? I don’t think so: They looked too different. Even present-day hunter-gatherer groups have been observed to engage in violence when they encounter each other.
Ok for the "looks" part, but violence is really not counter-evidence of interbreeding. Systematic rape is an ordinary part of war, and it would of course produce offsprings (biology permitting).
That's a strange quote, and just wrong. There's the 1/8 Neanderthal (7/8 Cro Magnon?) buried with normal burial rituals in a 40,000yo site. If that's not evidence of 'crossing paths', (three generations of integration into a tribe?) I don't know what is.
Even on the looks front, we’re a species with diverse tastes. Some humans like metal rods stuck up their urethra. The idea that a Neanderthal would universally be prohibitively ugly is a bit silly.
Agreed, and given circumstances, it doesn't take more than a few successful pairings to propagate a new hybrid species if the environment is favorable to their survival.
I don't know how much we can extrapolate from modern humans to present-day, but modern psychology research suggests that what people find attractive or repulsive is extremely early-experience-dependent. I suspect a homo sapiens society living near a Neanderthal society may not grow to find them as repulsive as, say, a homo sapiens society that has rare contact with Neanderthal. And if a child was raised by Neanderthal / homo sapien parents, or adopted from one tribe to the other, I have no particular reason to assume they'd find either species repulsive.
Even regarding looks, when I look at images of Neanderthals such as this guy on the Smithsonian's web site (https://humanorigins.si.edu/evidence/human-fossils/species/h...), I see a human, and nothing more. Leaving aside the idea that Neanderthals probably lived in groups with other Neanderthals, and modern humans with modern humans, I don't have a problem believing they may have intermated.
Yea I also found this really surprising. Like you said, rape is one option, but you could still expect some mixing even if 90 or 99% of encounters were violent.
Isn’t the definition/line drawn for the delineation of a species (compared to a sub-species/variety/variant) if offspring will be produced that can also reproduce.
Horse vs Donkey == mule (which can’t reproduce) being one of the few examples where anything is produced, and why they are considered different species.
One challenge here of course is while we have examples of Neanderthal/human hybrids, we don’t have enough of them to say it’s anything but a crazy fluke. But that could just be due to not having enough data points, not due to it being hard.
If it wasn’t a crazy fluke, then yes they shouldn’t be a separate species.
Maybe the implicit question is how different can an interpretation/assertion from one field of study be from related fields before the fields need a reorganization for coherence’s sake?
My intuition is that the gene acts as an data ledger relatively more reliable than other physical artifacts both in terms of semantics and availability. I’m open for that view to be falsified and it would be preferable for concordant interpretations and presence of molecular and other types of evidence.
Species like the elusive computer programmer, often avoiding sunlight at all costs, are one of the many species included, lol. I know HN hates satire but I can't stop humor.
This is a very very very dangerous subject for your career. I'll be honest I'm not sure any legitimate journal would publish anything further along in this line even if it was replicable, which scientist would risk peer reviewing something that could lose them their job.
A domestic dog, wolf and coyote can all breed together and all produce fertile offspring. Then you look at genetic variation between the three species.
All sorts of quacks still get tenure. There’s always a university willing to accept most heterodox views.
I see regularly comments along those lines on the Internet. I’d like some examples of “unpublishable scientific theories” that are not obviously bunk, as opposed to just controversial. Otherwise it is mostly a convenient bogeyman for bunk mongers.
Also, replicability seems a strange concern for this field. We’re never going to have an Earth Mk2 to test hypotheses.
Fascinating case. Quite a lot of emotions as well. I am not going to derail the discussion, though, as this leads to a deep rabbit hole.
To stay on topic, this is not an example of career-ending article, because he’s already retired, and nevertheless still affiliated with both Georgia Tech and California Polytechnic State University. He also himself says that the un-acceptance of his article is unprecedented, so this is hardly representative of anything.
Yes this was an unprecedented case because it was rejected after being peer reviewed and accepted. If they are going that far to censor inconvenient truth imagine how often good papers are rejected in review or not even written in the first place because the would be author knows what would happen.
Why? He quite clearly states that " All modern humans are clearly, morphologically H. sapiens." Do you suspect that further research along this line will disprove this?
I think it's just a bad article title that doesn't explicitly clarify that we're not talking about existing, modern homo sapiens.
Piddling about the taxonomy of extinct species isn't problematic, but I could see a mob misinterpret this as him saying that not all living humans belong to the same species, and go on a witch hunt over the misunderstanding.
However, if some evidence started emerging that modern humans were not all the same species (whatever that actually means in practice) then I think the above comment applies. No one with a reputation to protect would touch that bit of truth with a ten foot pole.
Because the implication of his writings is that it would be consistent with taxonomic treatment of other animals to classify certain existing groups of humans as different subspecies or species. Which strays too closely to so called racism.
I often wonder how many decades of progress political correctness (different from ethics) has cost us when it comes to science (when it's sound, provable, and replicable).
Sometimes I feel bad for the people whose legacy was tainted by scientific racism, especially if they lived to see its end and changed their opinions accordingly. Lovecraft is an example of this.
Oh he never stopped being a xenophobe, but he drew a line between his personal dislike and the idea that other races were inherently inferior. This is a good read: https://motifri.com/lovecraftcontext/
I like to think that if he hadn't died so young his personal tastes might have matured.
I see what you're getting at, but this is a bit of a motte-and-bailey argument. While it is literally true that widespread acceptance of racism and sexism was (and is) motivated by a desire to avoid being wrong in the eyes of prevailing politics, that's not what the specific term "political correctness" popularized in the early '90s referred to.
The NYT opinion article that popularized the term said:
> Affirmative action is politically correct. So too are women's studies, gay and lesbian studies, and African-American studies, all of which are strongly represented in the scholarly panels at such professional meetings as those of the American Historical Association and the Modern Language Association. [...] Biodegradable garbage bags get the p.c. seal of approval. Exxon does not.
And Bush Sr. gave a speech shortly thereafter decrying it:
> The notion of political correctness has ignited controversy across the land. And although the movement arises from the laudable desire to sweep away the debris of racism and sexism and hatred, it replaces old prejudice with new ones.
They and all the other media figures and conservative politicians and so forth in the early '90s would have all looked at you confused if you claimed that racism and sexism, themselves, were forms of political correctness.
If your argument is that public pressure to conform to racist and sexist cultural consensuses was bad for scientific research, it does not actually help the cause to defend opponents of "political correctness" who advocate for the freedom to express now-unpopular racist and sexist viewpoints.
> If your argument is that public pressure to conform to racist and sexist cultural consensuses was bad for scientific research
My argument is that public pressure to conform to the political norms for its time is always bad for scientific research, regardless what the political norms are. The political norms are what is called "politically correct", things that you should believe because otherwise society will become hostile against you.
Political correct pressure on science is similar to banning all smoking health research that isn't funded by tobacco companies. Sure tobacco funded research is still research, but it will be extremely biased. The same about politically pressured research. The pressure to confirm racist ideas lead to a lot of bad science in the past. The pressure to confirm modern political ideas lead to a lot of bad science today. Those two works in exactly the same way. However since I live today and not in the past I care about the problems science face today rather than the problems it had a long time ago that are no longer relevant.
I think what I'm saying is that what is called "politically incorrect" is a small slice of the things that will cause society to turn hostile. Moreover, in fact, many things that are "politically incorrect" simply won't result in hostility that effectively suppresses work at all (after all, the two quotes I gave earlier were from the most influential newspaper in the world and the president of what had just become the world's only remaining superpower).
That is, I agree with you that public pressure to conform to political norms is bad for scientific research, but I am arguing that a specific focus on avoiding "political correctness" means that you in fact succumb to a lot of other (present-day) political norms, which is the actual thing that is bad for scientific research.
Taking your tobacco-funding example - you are, of course, correct, that tobacco-funded research is extremely biased. Suppose someone says that this research cannot be taken at face value, and Philip Morris accuses that person of anti-tobacco bias, of succumbing to anti-cigarette political correctness, of conforming to political pressures about how terrible Big Tobacco is. Who do you side with? There are two accusations of bias here; how you do determine which one is correct?
The heuristic "Political correctness is bad" is clearly unhelpful in this scenario; it cannot guide you to the correct decision. If you want a more meaningful principle, you have to look deeper at things. Even your phrasing "conform to the political norms for its time" is a more meaningful phrasing - but then an obvious consequence is that opposition to political correctness was the political norm of the early '90s when the president and the Gray Lady were telling people how bad political correctness was.
> but I am arguing that a specific focus on avoiding "political correctness" means that you in fact succumb to a lot of other (present-day) political norms, which is the actual thing that is bad for scientific research.
Right, this is a really hard topic. I didn't say I had a solution, just saying it is a problem. There will always be a lot of political influence in research topic related to controversial things and people living under that influence will have a hard time identifying it. The racists 70 years ago probably didn't think they were doing anything bad etc. But today we recognize it as bad.
> but I am arguing that a specific focus on avoiding "political correctness" means that you in fact succumb to a lot of other (present-day) political norms, which is the actual thing that is bad for scientific research.
Yeah, you have counter movements and resistances. But if the context is non-stem non-economic researchers at universities then it is pretty much only in one direction. There is no allowance for the other side to do much research in those areas, meaning research in those areas is a one sided politically correct story.
If we let tobacco companies publish research, and other people publish research, then people can look at the two and make their own decisions. But if you basically only let one side research then you will get bad research.
You can take the words and use their individual meaning to come up with any definition you like to make any argument you like. However you don't win arguments by arbitrarily definition words or phrases to be what you would like them to be. You definition factually is not the definition of political correctness. As such historical racism and sexism were not political correctness.
> Political Correctness- the avoidance, often considered as taken to extremes, of forms of expression or action that are perceived to exclude, marginalize, or insult groups of people who are socially disadvantaged or discriminated against.
> In 1934, The New York Times reported that Nazi Germany was granting reporting permits "only to pure 'Aryans' whose opinions are politically correct".[2]
The definition you read there is just what is politically correct today, it isn't what the term really means. Racism was politically correct back then, it isn't politically correct today.
> However you don't win arguments by arbitrarily definition words or phrases to be what you would like them to be
> the avoidance, often considered as taken to extremes, of forms of expression or action that are perceived to exclude, marginalize, or insult groups of people who are socially disadvantaged or discriminated against.
Aren't you taking an arbitrary definition (un-sourced from google/Oxford Language) to win your argument?
Here is Merriam-Webster's
> conforming to a belief that language and practices which could offend political sensibilities (as in matters of sex or race) should be eliminated
Seems like both are acceptable modern-day usages... like other terms a difference between capital vs lowercase might help here like... "republican" vs "Republican", "democrat" vs "Democrat"
"opponents of "political correctness" who advocate for the freedom to express now-unpopular racist and sexist viewpoints."
You had me until this. What I don't like about PC isn't when actual racist comments get shouted down or whatever, which is what your comment implied. It's when non-racist statements are misconstrued as being racist in order to silence political opposition. For example when opposition to affirmative action is enough for some activists to try to get someone fired.
I strongly suspect that much of the messiness in empirical biological studies would be deconfounded if we were generally more willing to classify humans into narrower ethnic groups. For example, different groups of people are likely optimized for different diets, in which case insufficiently breaking down the ethnic makeup of your study cohort would lead to weak or contradictory evidence when applied to populations at large, as we tend to see. The same likely applies to various supplements, medications, and probably even psychological studies including behavioral and medical interventions for abnormal states.
I can understand the hesitancy to do so but I think most people, including scientists, are not aware of the likely cost. It is possibly to classify humans into races/subspecies without resorting to racial discrimination or animus - the same way we currently celebrate so called diversity.
I do believe it would likely have implications for the interventions which certain pockets of our society are attempting to install to correct for racially correlated inequities.
If it's repeatable, why does it deserve to be censored? Science is empirical, if it can be measured, measure it. If you can re-create it, do so. The very nature of it being "replicable" means it is worth publishing and discussion.
Modern social media has ruined many careers unnecessarily. The mob mentality sometimes wins and destroys people that it shouldn't. Social media can be as much a disease as a benign influence.
Because a lot of what we think we know might actually be false. For example the empirical idea that there are two biological sexes. That is false, despite seemingly being well established:
> Sex Redefined: The Idea of 2 Sexes Is Overly Simplistic
> Biologists now think there is a larger spectrum than just binary female and male
> “My feeling is that since there is not one biological parameter that takes over every other parameter, at the end of the day, gender identity seems to be the most reasonable parameter,” says Vilain. In other words, if you want to know whether someone is male or female, it may be best just to ask.
archeologist will find a person with scoliosis and think its a significant branch in evolution when it’s the same species/whatever with a birth defect that offers no advantage or disadvantage to reproduction
While this is not impossible, the argument usually goes that there are so few specimens that get fossilized that it's extremely unlikely for a particularly unique specimen to have been the one getting fossilized. Basically fossilization is "pick a random individual", and the odds of picking an individual with a rare condition are going to be very small.
A slight tangent, but I sometimes wonder how 'humanoid' any potential intelligent alien species must be, if they exist. Some science fiction writers depict alien species as quite morphologically similar to humans – Romulans and Klingons in Star Trek – or radically different – Hutts in Star Wars, Hanars and Krogans in Mass Effect. If you take a quick look at "Star Wars alien species" or "Mass Effect alien species", most of the differences imagined by writers are around the head shape, and the overall distribution of muscle mass around the rest of the body. So most alien species you meet in pop sci fi is 90% identical to humans, with a different head. Human heads in this sense are pretty basic. We don't have a leku like Twi'leks, ridged foreheads like Klingons, long necks and slender frames like Kaminoans, a small ring of horns and skin patterns like Zabraks, or scalp-crests like Asari.
But if we did, would these traits ever go away? Would human evolution eventually "revert" us back to our present form? Because something tells me that we wouldn't, and the selection process would basically say "good enough". In other words, the reason we don't look like Asari or Twi'leks is probably pure luck, and the reason alien species may look the way they do (again, if they exist) is also pure luck. But they probably share some of the general characteristics of humanoids, such as limbs not necessary for motion and with opposable fingers, a head separate from the rest of the body, etc.
> I sometimes wonder how 'humanoid' any potential intelligent alien species must be, if they exist.
TV uses humanoid aliens because they're easy to cast :)
Just look at the other intelligent life on Earth. Some birds, whales, elephants are near the top. If we hadn't nearly wiped elephants out maybe in another 10 million years they'd be making spaceships with their trunks (which have a fine manipulation ability approaching the human hand).
A little further away evolutionarily, jellyfish are remarkably intelligent and seem to even have individual personalities, and they don't have a brain.
As retrac says, it’s easier to cast for humanoids. And decades ago the special effects technology was nowhere near what we have now, so there were fewer options for more unusual forms and they were expensive.
Novelists had no such restrictions, so Larry Niven could create Pierson’s Puppeteers in 1966:
They're different from humans, but much closer than we expect: mammals (apart from the birds, sure), with similar skeletal structure, similar overall "how it works" biology (brains, skeleton, digestive system, circulatory system, etc)
The closest "intelligent alien" we know of is the octopus. That's really something else. But even then a lot of biology is shared.
If you want to get creative don't think of humans mating neanderthals, think animals re-evolving from an earthworm or a jellyfish.
> I sometimes wonder how 'humanoid' any potential intelligent alien species must be
Great question. I enjoyed Andy Weir's take on this in his most recent book Project Hail Mary. If anyone hasn't read it yet and they're intrigued, I would suggest picking it up without finding out any more about it.
> selection process would basically say "good enough".
You ever start a refactor, find some dead code, and realize you could work it into a new feature? I wonder if vestigial organs are ever reused like that.
I know we're both just being trite, but it is an interesting point that nearly all of our genetics are concerned with the "inside bits" of our proteins, organs, and so on. Whereas when we talk about a hypothetical extra-terrestrial being that has the basic external configuration of a human, that could well be a sulfur or graphite-based life form, or something else entirely.
Basically it could look like a smooth, slender, big-headed human but under the hood have much less in common with us than an earthworm does.
alien life may be so different from what we are familiar with ... that we may not even recognize it as life when we encounter it first
the differences may be in sheer size of the organism -- think licens and moss at planetary scale -- or even loosely collected soup or vapors of chemicals
the difference could be in metabolism that we may need 4-5 generations of humans to see them live and grow and die -- or they might live for only a fraction of a second
just like there are billions of microbes living in each of our bodies (and they have no mental capacity to comprehend us or our world) ... we may in-turn be microbes inside a much grander macro-cosm that we can never wrap our heads around
I would hardly classify these as radically different. Hutts have two arms, two eyes a nose and a mouth, and vocalize similarly to humans. Krogans are very much humanoid as well and follow the same basic body plan.
I'd agree about the Hanars. Better examples of radically different would be the Dwellers from the Algebraist, the Tines from A Fire Upon the Deep, or Alex Ries' Birrin[1]. Even then, they are all relatively human-like in their culture.
Not at all. An example is the intelligence embodied in cephalopods such as the octopus. The fork between us and them occurred maybe 600m years ago. Suggested reading:
Yeah it's probably not pure luck but instead complete adaptation to the particular environment.
Now you talk of aliens breathing and eating meat which can be conceived but... what of a pure liquid helium planet ? The intelligence there might be completely different, with reproduction cycles we cant imagine and energy transformation that may not even require eating other life form like us.
Some humans have freckles and others have thicker hair. As evolution has no mind or will, if there is nothing pressuring these traits to leave the gene pool then it would be negligible probability that they do.
Same with any morphological traits, I reckon (I am not an evolutionary biologist).
This was an interesting article, but I found this editorial warning a little odd:
> Please note that this article includes images of human remains.
I don't think I've ever seen a warning like this before in any anthropological publication, or even in a museum or exhibit. I can't say I've ever found looking at skulls to be particularly weird or shocking, especially if they are extremely old. But, is this a warning that people or the general populace are requesting or feel is necessary? Or, is it purely an editorial decision?
> I don't think I've ever seen a warning like this before in any anthropological publication, or even in a museum or exhibit
I went to the Carnegie Museums in Pittsburgh a couple of weeks ago, and they had warnings for if an exhibit had human remains in them (even if they were not visible, I.e. in a mummy).
They also had a short blurb on the ethics of displaying human remains, especially if the remains on exhibit didn't/couldn't give consent. I found it very thought provoking honestly.
To extend it, I found it interesting that there was a lot of discussion on the ethics of showing human remains (taxidermy, in alcohol solution, bones, etc.), but then they showed a lot of animal remains and there was no discussion on that, especially when I would assume that many of the animals shown in the museum were killed for the specific reason of having them on a museum or for study.
This religious ban does not include pictures of human remains, does it? And the warning mentioned in the root comment of this thread is located on a website.
Edit: I wonder what is downvoteable about my original comment. My Jewish colleagues do not eat pork, but they do not avoid depictions of it, such as photos in a menu. I guess it should be similar in the case of Kohanim being forbidden to come in contact with human remains. Direct contact is very different from a painting or description.
> I wonder what is downvoteable about my original comment.
Lazy randoms who disagree also often feel entitled that they don't have to explain their displeasure or engage in meaningful discourse. Instead, they will try to silence you for having an opinion different than theirs. Also, sometimes I think it's passive aggressive social win-lose mentality or maybe even gaslighting. Best to not care about popularity and move on seeking discussions of valuable insight rather than dwelling on being clobbered for no apparent reason.
That’s correct, pictures of human remains are allowed. I was referring to the museum situation. Many religious Kohanim would avoid going to a mummy exhibit.
Skeletons are taboo in Chinese culture. All sorts of companies and organizations has gotten much more aware of Chinese things the past few years, so maybe that is why.
Other people bringing up cultural differences is appreciated, because to me that warning implied pictures of cadavers. Upon assessment, don't think I've ever looked at a skull (or any other decontextualized bone) and considered it "human remains." An entire skeleton, sure, but even then...faux skeletons are such common imagery throughout America, I've become 90% desensitized to what they're a representation of.
It seems like an unnecessary accommodation for the easily offended. This sort of pandering cedes more and more control to the whims of sheltered, infantile crybullies.
According to their about us page, the warning fulfills some commitments they apparently have (clarity of reporting and empathy for example). So it might very well be a decision by the editorial team.
It's not too odd that some people don't want to look at gore. For most of us corpses sterilize, become like objects the older they get, but I don't why that's anything but arbitrary.
Aboriginal Australians and Torres Strait Islanders get warnings that what they're about to view may contain depictions of people that have died. Not depictions of dead people, but depictions of people who have died since they were filmed or had their picture taken.
On the contrary, you never knew who might be reading. Maybe there's a kid who gets really freaked out by skeletons? It's not hurting you to have the warning there.
[1] What is the design behind this article called?
[2] No matter what I do in my browser settings, it seems like text is small without zooming in individual websites. I need to zoom in to 200% to be able to read it. Is this just a recent trend? https://imgur.com/a/6C2xJkG
By 1963 it was again okay to talk about multiple hominid species, so the scientific consensus started moving back in that direction.
I find this fascinating because I never realized science could be so political.
More interestingly still, when the author talks about species being mis-identified as homo sapiens despite stark morphological differences and that they probably represent an extinct close relative, that gave me a funny gut feeling. Felt like dangerous territory to talk about …
Fascinating
What seems sort of funny is that now that the existence for potential taboo censoring has been recognized, in recent decades there are several charlatans, conspiracy-mongers, or other ideologues who paint themselves as subject to scientific taboo despite "being accurate" in their own minds. The pendulum has swung towards over-acceptance of claims.
This was a time referred to as the "nadir of race relations" in the US, and if you read the output about humans as a species from that period, you'd be a lot less impressed. It's all out of copyright and a lot is available online. It's not what most of us would look at as science, now. It's more like mythmaking.
So, the "scientific consensus" of that era involved a number of scientists from many countries who agreed with policies and goals that, in retrospect, we now see as not only politically partisan but also specifically aligned with Nazi political ends.
Your argument is a very common one but very flawed. Antisemitism, ultranationalism and eugenics aren't bad because the Nazis did it. It's exactly the other way round!
Eugenics are just as flawed and criminal when a Swedish doctor or a British politician advocate for it.
If the scientists of that era said that certain humans were an inferior species to Homo sapiens, and the scientists after World War II said that's not true, we shouldn't assume that the pre-war view was pure untainted science and the post-war one was the result of overcorrecting for political/moral reasons - we should consider the possibility that the pre-war scientific consensus was tainted by political/moral views that we now rightly reject.
Its incredible how little people know about the period in American history between the end of Reconstruction and the start of WWII beyond just: "WWI", "Market Crash", "Great Depression".
Following one theme: Nadir of race relations, Red Summer of 1919, and Great Migration (one of the largest movements of people in history).
https://en.wikipedia.org/wiki/Nadir_of_American_race_relatio...
It makes it so much more difficult to have an objective discussion about the past simply because people are unaware of it, or simply understand it at a very high / hand-wavy level. "Some bad stuff happened then eventually it stopped."
I want to say yes, because how are you even distinguishing that world from this one? There exist humans who are fifty IQ points smarter or dumber than other humans who also exist.
The batshit crazy idea is that these differences are caused by or intrinsically bound with skin color.
As for sex differences, here's the money quote:
https://en.wikipedia.org/wiki/Sex_differences_in_intelligenc...
> All or most of the major tests commonly used to measure intelligence have been constructed so that there are no overall score differences between males and females.
We believe in egalitarianism, therefore IQ tests that show a sex difference are wrong, therefore we use IQ tests that show no sex difference.
Now, if there are biological differences between the sexes, they could not only go either way, they could go both ways. It's possible that on average women are better at X and men are better at Y, so you could really design a test to show whatever result you want.
It's also obviously the case that no matter what the averages are, the world's highest-scoring male will almost certainly have a better score than the world's lowest-scoring female and vice versa. So arguments of the form "women can't do X" are stupid even if you can find a statistically significant difference in the averages using some metric. Because most people are not exactly average.
Discrimination is the assumption that all members of a group are the same.
Sure but they're not all in the same ethnic group. What if a populous group had the peak of their intellectual curve far down the range? If, say, Gauls/French people were almost entirely simpletons equivalent to someone with Down Syndrome? Would they be enslaved and turned into a worldwide servant class? Every other group that were thought of as being inferior can be demonstrably equal to their oppressors but I think a world in which they weren't could be very different.
It takes a long time, an evolutionary timescale for that sort of difference to emerge. There’s an argument that the reason that modern humans are so homogeneous is because we wiped out all competition long before we had recorded history or civilisation.
https://mankindquarterly.org/archive/issue/51-4/2
The brain is just another blob of flesh, and what we understand of its capacities suggest it's at least partially inheritable. You'd have to ignore a lot of evidence to believe that all humans are intellectually equal. If there is variation and there is mutation and there are different pockets of populations, there are going to be evolutionary differences between them. Then in terms of sexual selection, we'd have to believe that intelligence as a criterion for mate selection is equally important across cultures, and also impacts offspring fitness the same across all cultures and environments -- vs, say, disease or sun resistance in the tropics. Otherwise, differences would naturally arise over time.
The tricky part is coming up a way to define, much less measure, "intellectual capacity" across different cultures and ways of knowing. IQ tests are pretty biased and arguably a useless measure of evolutionary fitness in many human cultures. Even if you could create the perfect cross-cultural IQ definition and test, administering and collecting such a thing would be nearly impossible in a world where many countries don't even have proper birth records or thorough population censuses (even a basic count, without in-depth testing).
We already know that, within the upper and lower bounds, there can be great variations of "intelligence" WITHIN populations group, as well as smaller differences between them. But we lack the methodology and cultural transparency to be able to accurately measure whether the cross-cultural error bars fall within the intracultural ones. That's not for lack of trying, mind you... many careers have either risen to infamy or else have been destroyed for daring to suggest such things.
In other words, it's not that all humans are equal, it's that we're SO diverse it's hard to group us into neat little groups, whether by race, ancestry, skin color, intelligence, or any other genetic factor. Because the underlying genes themselves don't work that way. They're always changing and competing.
The principles of egalitarianism are a cultural ideal (not shared by much of the world, mind you), not necessarily scientific observations. The scientific input to the ideal, if anything, is not that "the are no differences between groups" but "there are so many differences that these groupings don't really make sense; there are a million other equally valid groupings".
Surely we already know that there was research (whatever its quality or rigor) back pre-WWII that was supposed to defend racist theories. And that’s political. So I don’t understand why we would be surprised that there was a (political) backlash once millions ended up dying in part because of that kind of research.
I have that funny gut feeling, too; I suspect he's more than half-way to deciding that modern races are actually separate species.
"It's snowing so there can't be unfrozen water in the air" or whatever.
Horse and donkey, for example are not the same species because their offspring, a mule, is not fertile.
I think it was Richard Dawkins who extended this idea through time. We could mate (sorry) with our immediate ancestors, who could with theirs, etc. and in fact there's a continual chain like that all the way to any other mammal. When did we stop being our ancestral species and become H. Sapiens? No clear line.
This is really just an instance of Sorites paradox. But the inability to draw a precise line between two (or more) states does not mean there aren't two (or more) states.
What is it that makes a PB&J clearly a sandwich, and excludes a stack of pancakes with butter in between - and doesn’t exclude a club sandwich.
More generally, the key delimiter for sandwiches is the aspect ratio of the individual items contained by the bread. For something to be a sandwich, all of the major items inside must have one dimension which is substantially smaller than the other two. Sliced meats, bacon strips, cheese slices, sliced vegetables, lettuce leafs, spreads, patties, etc are all valid. Thinly spread peanut butter and jelly between bread is a sandwich, but a bread bowl with a pool of jelly and peanut butter where the depth is comparable to the radius would not be a PB&J sandwich. Flat cheese slice between bread is a sandwich, mozzarella sticks are not sandwiches. Hot dogs are by default not a sandwich, but if you cut the hot dog into thin strips it becomes a sandwich. An oreo is a sandwich but a quadruple stuffed oreo is not. The only commonly accepted sandwich which this definition claims to be a pseudosandwich is the meatball sub.
Regardless of these facts and it not meeting your criteria, it is still both in common usage and by explicit name a sandwich!
(Also, love it!)
(Sorry, can't resist keeping this going, this is some good discussion).
It's true I guess that the aspect ratio for most ingredients is 'flat', but many are thicker than the bread, and the whole sandwich is 'sideways' aspect ratio wise.
That said, just because something has a word in the name doesn't mean it's a subset of that category. Strawberries aren't berries, english muffins aren't muffins, prairie oysters aren't oysters, black pudding isn't pudding, etc.
I don't really get how your prescriptive rule means open faced sandwiches somehow "contain" their contents. Then again, since I don't believe in being prescriptive, I don't really care to think hard enough about the contortions of logic required by your approach.
A container is something which contains. If you can manipulate something by the bread part and the contents stay put, they are contained. While the aspect ratio rule may be legitimately controversial, if you don't restrict your definition of sandwich at least to stuff contained by bread then what isn't a sandwich?
The whole point of this exercise is to taxonomically categorize foods as being sandwiches or not sandwiches, how would you do that without being prescriptive?
https://en.wikipedia.org/wiki/Platonic_idealism
Now that you’ve said this I do remember Richard Dawkins making that argument. That’s pretty compelling.
It's mostly based on DNA analysis these days, I think.
Based on the admixtures of Neanderthal and Denisovan DNA in modern humans, we once had a lot of sex with those other humans (and they with us), resulting in fertile offspring, but the differences between us and them are pretty meaningful and probably worthy of not considering us and them just subspecies of the same species.
For example, Neanderthals probably could not vocalize in the same way that we do; and being capable of speaking is quite an important distinction. They had very different anatomy, including that of important joints (shoulders).
The bigger problem are things that have massive morphological differences but can still successfully interbreed, such as dogs, coyotes and wolves. They produce fertile hybrids and there is good evidence that this occasionally happens in the wild, but nevertheless it is rare and they have clear, stable morphological distinctions, even in areas where they overlap.
Even worse, that definition is entirely useless for paleontology, as it is impossible to know if two individuals species could even interbreed, nevermind knowing if their offspring would be fertile. Even modern genetic evidence (which is extremely rare for fossils anyway) is very open to interpretation on the matter of potential interbreeding ("Neanderthal" genes in modern humans could more or less as easily be common genes older than both H. Sapiens and Neanderthals - we have far too little evidence to be sure, and no chance of genetic material from an older ancestor).
Or, in this case with ancient human remains, there's no way to check viability when all subjects have been dead for a hundred thousand years.
All can interbreed all can have fertile offspring with each other. Then look at the genetic variation between all three species.
Yeah this type of science is the stuff which destroys careers...
This is the opposite of a circular argument, this is the foundation of inductive reasoning. A = B and B = C thus A = C. If something has unambiguous neanderthal DNA but doesn't look neanderthal-like, then your idea of what is neanderthal-like is discredited.
In the case of hominid interbreeding, we can see genes that are common in neanderthals appearing in non-african modern humans. Had these genes existed in our common ancestor, they would be present in african populations as well. The opposite being the case, the only way for those genes to get there is if only some people descend from neanderthals, which in turn requires successful interbreeding.
Suppose humans migrate to Europe from Africa, then have some local divergence from their ancestors. Then those humans interbreed with neanderthals, so that those divergent genes spread within the neanderthal population as well.
Putting aside the question of whether the existence of interbreeding makes neanderthals not a separate species, it's going to be difficult to tell where those genes originated.
Suppose the first person to have those genes was a human who bred with both humans and neanderthals, but it so happens we have fossils of some of the earliest neanderthals with those genes and not the earliest humans with them.
Then you could have the result that some "neanderthals" descended from humans but not vice versa, and be unable to distinguish that from the other way around.
We do indeed find neanderthals who descend from humans, interbreeding went both ways. For example we can see that around 100,000 years ago, the neanderthals' y chromosomes were almost completely replaced with a modern human y chromosome whereas even as late as 38,000 years ago there were still neanderthals with purely neanderthal mitochondrial DNA.
It is even more surprising that people dismiss genetics in a age when national borders are closed based on such analyses of COVID genomes. The nextstrain resource is a great way to get an intuitive grasp of what genetics gives us. https://nextstrain.org/ncov/gisaid/global
For those who aren't scientists, we are sometimes referred to as H. sapiens sapiens.
Neanderthals / Neandertals are sometimes grouped as a subspecies of H. sapiens as H. sapiens neanderthalensis.
Ideas are interfaces. And interfaces provide utility.
The very notion of "biological species" is based on the underlying notion of philosophical species, that specific classifications. Evolution turned this on its head by noting that species evolve (that is, change), over time. There is no such thing as an absolute species in the earlier philosophical sense.
https://www.etymonline.com/word/species
So the question becomes "where is it useful to define boundaries between species?", with various arbitrary boundaries proposed. The question isn't of their arbitraryness, but of their utility.
And those definitions are ultimately a relationship between us and the universe we're attempting to define.
You can drag in Wittgenstein and a whole bunch else. Knowing some of the philosophical background is useful, less so because a particular view is right, but more because virtually any argument or viewpoint proposed has been offered before, and many of the strengths and weaknesses discussed. Usually to great length.
Because, if I did understand you correctly, I completely agree with that.
With gene sequencing and techniques such as molecular clocks we can determine evolutionary trees and the approximate time between mutations. This gives us a fairly clear understanding of what current species are placed where on the evolutionary tree --- where you draw the boundaries still has some ambiguity, but it's usually possible to at least say which of two specific samples is closer to or further from a third.
We've also realised that genetic inheritance and transfer is not strictly along descendent lineages --- there's swapping of genetic material, espeically between living organisms and viruses, as well as amongst complex organisms and bacteria. Your mitochondria --- common to nearly all eukaruyotes --- is itself an entirely distinct organism which has become entirely symbiotic with you.
So there's nearer and further, and indirect inheritance. But there remains a great deal of cases --- remember, 99.9% of all life forms on Earth have gone extinct --- where we simply do not know. Or where knowledge isn't sufficient to make a clear or unambiguous distinction or classification.
Jainism has the concept of Anekantavada, "many-sidedness", exemplified in the fable of the blind men and the elephant. It's useful to recognise that our perceptions are arbitrary --- they're dependent on both the particular subset of reality we're observing, as well as the limited channels through which we're making that observation, and the conceptual frames by which we organise it. That said, many sidedness is not any sidedness --- all interpretations are not equivalently valid. That's the gist of a utility model of epistemology: usefulness is context-dependent, but also exists on a spectrum, from high usefulness (greater truth value) to low (likewise).
Arbitrary is not indifferent.
Mind as is usually the case I'm speaking of an area in which I have largely lay knowledge, though I think I'm not going too badly astray.
I get that having formal names is useful, and basing those names on ancestral characteristics seems sensible. But it doesn't seem to take into account that this is a moving target: everything is evolving, and populations are not going to stay the same over time. Trying to classify every living thing into neat categories is like herding a million very slow cats. Especially with palaeontology, where the timespans are large enough for evolution to really matter.
Using the most prevalent definition of species, the one listed on Wikipedia, we don't have "too many species lumped together into Homo Sapiens", we actually have too few. We know all or almost all "species" since and including Homo Erectus were able capable of interbreeding, meaning they were actually single species.
The trouble is they are trying to use definition that has been developed on observation of the current state that is not suitable for classifying evolving organisms over long periods of time.
That might not have been a huge problem when discussing other animals, but for some reason we pay much closer attention to precision of resolving our own parentage and that is when the definition falls short of being able to serve the need.
While this is what we were taught in grade school, actual biologists don’t use this children’s definition anymore than actual quantum physicists say atoms are like little solar systems.
There are plenty of separate species that are physically capable of producing fertile hybrid offspring. Dogs and wolves and polar and grizzly bears are a couple obvious examples. Also plenty of species don’t reproduce sexually, so defining species in terms of sexual compatibility isn’t even well defined.
Can you link me to the definition biologists use? I googled for a minute and didn't get very far.
Wikipedia (https://en.wikipedia.org/wiki/Species): "A species is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction."
What is the correct & concise definition?
https://evolution.berkeley.edu/biological-species-concept/
https://evolution.berkeley.edu/other-species-concepts/
IMO it's that "species" is a term coined by older, less-informed biologists who didn't yet understand all the nuances of genetics, and created a taxonomic system based, erroneously, on superficial differences in appearance. It's like how old scientists believed in "ether" to describe the mysteries of space and "humor" to describe the mysteries of the body. Species is what old scientists used to describe the mysteries of genetics.
Equality is a human cultural construct, a social contract that attempts to minimize in-group violence. It is itself a cultural evolution, a relatively recent one in the West, longer-lived than that in other cultures, but altogether very limited and mostly only applied to some convenient in-group du jour, not humans around the world and certainly not to hominids at large.
Equality has no real evolutionary basis. Evolution depends on inequality in the face of selection pressures. May fit individuals breed, may adaptable populations persist, and may the sexiest genome win.
Scientific racism failed both because of changing social norms and because taxonomy-by-appearance was doomed to fail upon closer inspection, not because humans are inherently equal... we're anything but, and those "self-evident truths" are believed by no one in particular, not even grade school kids. It's ironic that the nation who says that on one hand has, on the other hand, produced one of the most unequal societies in human history.
If society is ever to actually become egalitarian, it must be because we -- by social contract or force of mythology -- place equal value on each individual, not because our genetics are the same. We're not clones and we're all better and worse at some things, and most of us are completely mediocre at everything except, maybe, being an adaptable hairless ape between ice ages in the temperate zones of a wet rock floating around a star.
In other words, we can't morphologically evolve our way out of racism, but perhaps -- someday, if we survive these next few decades -- we can culturally evolve more egalitarianism. Genomes aren't the only unit of information reproduction anymore. We can only hope culture will succeed where nature failed.
There isn’t one. “Species” is an abstraction, vague when you look too closely, and increasingly meaningless when you move from animals to plants to fungi to bacteria and archaea.
There’s just no way to decisively say exactly when two closely related organisms transition from one species to two.
You will find debate and varying methods but in the end for the professional scientist, it’s mostly an unimportant question for most because it’s obviously just vague and never possible to be perfect, and you have to ask “what’s the point?” of the really fine grained labeling which seems to only be done for the purpose of labeling.
Even the term planet has recently given us trouble. There we’ve adopted a definition, it’s just not fully agreed upon.
> A mathematical proof is an inferential argument for a mathematical statement, showing that the stated assumptions logically guarantee the conclusion.
Unlike all the other sciences, mathematics is abstract enough to allow for things being fundamentally simple and true.
In fact, most mathematics isn't done this way (though there's interesting work in the Lean community). Mathematical proof as it is actually done is far messier. Here's the paper that first came to mind (Probabilistic Proofs and Transferability, by Kenny Easwaran), though I'm sure there is a more canonical source: https://ucfc6eb8f695030deb8332de441a.dl.dropboxusercontent.c...
P.S. You're free to adopt a way of speaking in which you say the majority of graduate mathematics textbooks do not involve any proofs, but I think that's a revision of the term.
The bottom line is that there is no one correct and concise definition.
It's also obvious that the fertile offspring definition is not sufficient of you look at plants (pomelos, mandarins and citrons are rather obviously different species, but they are interfertile and most modern citrus species are their hybrids) or even more obviously, at bacteria or yeasts that don't even reproduce sexually.
"And the more specimens I study, the more I realize that most of the species designations don’t make sense. If hominin fossils were treated the same way as nonhuman primates, specimens currently lumped into the same group would be allocated to different ones."
Is this because the differences between purported groups is much greater than the differences within groups? Or because there's significant incentives to split groups in order to name more species/families/orders/etc?
The "traditional", extremely simplistic, definition of "species" is a group of critters who do not (normally) (fertilely) interbreed with another group (in the wild). Where there is evidence, Neanderthals and Denisovans, H. sapiens seems to have interbred rather frequently.
You can ask yourself why such an incentive wouldn't exist for finding new human species etc. The interesting part here is that humans are treated differently, not whether one is better than the other.
Reading natural sciences and eugenics books written prior to the 40s is fascinating - there's all sorts of casual racism and talk of different cultures of people as if they were completely different species. Global communications improved after the 40s, and it became progressively more difficult to pretend to be a scholar or intellectual in public if you had racist or supremacist biases. The current state of liberal acceptance and human rights in the modern world is part of a trend that was an incredibly radical departure from almost all human culture prior to wwii.
On the whole lineage does not imply capability, skeletal anatomy is not predict cultural level, etc. but because the great chain of being continues to drag our civilization down to its lowest basest form we belittle anything and everything that looks even slightly different than us. The fact that the null hypothesis in life sciences is that other species do not feel pain, do not have emotions, do not have cognitive process, etc. is derived from the abhorrent idea that only human beings have souls, or that the abhramic god gave man dominion over the animals. Is it a surprise then that some scientists have fooled the bigots by classifying everything as human? They know that by some criteria the lineages are sufficiently different to be classified as such, but there is no reason to give bigots ammunition for public policy.
The fact that there are many more clearly defined species is because "fitness" (which sometimes includes very random events happening) results in many "species" (or sub-species or variants or groups of mutants) to die out eventually and one lucky/fit group to survive.
With homo sapiens, like with many other only recently established species that didn't really happen. Or well, it did and that's why we have that taxonomy problem. But you can draw all sorts of lines. Of course the whole race topic comes in there too and what about people who are able to drink milk after a certain age and those who don't.
Species are sometimes distinct by very minor traits like that and not always by being able to have offspring.
So decisions are either made by people who establish species or by a majority of scientists agreeing, so more or less through a political rather than a scientific process. Of course that means it comes to a lot of bike shedding on these topics.
It's more a discussion about what the definition of the word species is than anything else.
1. speciation (as I understand it) has a clear definition: if two populations can mate, then they're the same species. I don't think preferences come into this - for lots of reasons (the vast number of possible interactions between populations, consent isn't required to produce offspring, etc). Saying "I don't think these people would fancy each other" isn't enough to define a new species.
2. the clear differences between specimens recovered does not reflect any clear difference between populations over time. The population of homo-ish living beings over the last 100,000 years is enormous, and we've recovered a tiny, miniscule, fraction of that. Classifying specimens is fine, but we shouldn't make the mistake of thinking that those specimens represent actual populations of humans. The sample size is too small to draw any meaningful conclusions.
I think the effort to minimise the differences between early humans is admirable, and should be continued. We have a tiny, farcically small sample size of evidence to base any conjectures about early humans on. Being inclusive about Homo Sapiens because it stops nazis being dicks about race is a good thing.
But not for the rest of lifeforms. Bacteria reproduce by cloning themselves and they can share genes laterally (between adults). And viruses are really more similar to computer viruses with intended replication errors than a lifeform.
http://www.macroevolution.net/
"Biology, hybrids, human origins and more"
Science should not be corrupted by the goal of countering human irrationality. It's no use: racists will use "science" to rationalize their positions whether or not mainstream science agrees. And it's harmful: the more science deviates from the pursuit of truth, the less we all can trust it.
Wouldn't that mean homo sapiens and neanderthals are the same species, given that many people have neanderthal genes and interbreeding is even a hypothesis for the extinction of the neanderthals?
Two members of a species make fertile offspring.
-----
This isn't a "perfect" definition, but the delineation is clear in most cases. In your case, a horse and a donkey make infertile offspring (aka: a mule), and are therefore different species but the same genus.
Nothing is effective enough for those extremes. But for the rest of society, specially those during school years, this is enlightening and hopefully enough to push agaisnt our inherent racism.
But that is only because we have this innate cognitive error.
In some sense, intelligence past a certain point should be sufficient to classify as “one of us” but such trans-species sentiment is generally limited to those who believe memetic reproduction is somewhat more important than genetic reproduction.
The one thing the article does not help me understand is the purpose of the classification. The utility of models to me is in the ability to make falsifiable predictions about the real world. Is it perhaps the history of our species and the way speciation works that is being contributed to? That seems reasonable and makes the taxonomic classification have some utility. But perhaps categorization is not a useful tool here, and tagging is superior, i.e. “neanderthal-like in feeding habits” and “sapiens-sapiens-like in communication habits” and so on.
https://en.wikipedia.org/wiki/Denisovan
> While certain similarities between our DNA and Neanderthal DNA have been interpreted as evidence of the two species interbreeding, these similarities could just be run-of-the-mill features of the genome, common to many species.
These and other arguments by the author to try and dismiss DNA evidence seems really suspect. The "circular reasoning" argument doesn't even make any sense. Neither does the scientists being too stupid to understand that DNA overlap between Neanderthals and humans is meaningless.
As a non expert, this makes me have doubts about the veracity of any of these arguments made in this essay
Ok for the "looks" part, but violence is really not counter-evidence of interbreeding. Systematic rape is an ordinary part of war, and it would of course produce offsprings (biology permitting).
I don't know how much we can extrapolate from modern humans to present-day, but modern psychology research suggests that what people find attractive or repulsive is extremely early-experience-dependent. I suspect a homo sapiens society living near a Neanderthal society may not grow to find them as repulsive as, say, a homo sapiens society that has rare contact with Neanderthal. And if a child was raised by Neanderthal / homo sapien parents, or adopted from one tribe to the other, I have no particular reason to assume they'd find either species repulsive.
Any doubts about that? There are literally people having sex with farm animals, why would Neanderthals be different?
Slightly nsfw.
Horse vs Donkey == mule (which can’t reproduce) being one of the few examples where anything is produced, and why they are considered different species.
One challenge here of course is while we have examples of Neanderthal/human hybrids, we don’t have enough of them to say it’s anything but a crazy fluke. But that could just be due to not having enough data points, not due to it being hard.
If it wasn’t a crazy fluke, then yes they shouldn’t be a separate species.
My intuition is that the gene acts as an data ledger relatively more reliable than other physical artifacts both in terms of semantics and availability. I’m open for that view to be falsified and it would be preferable for concordant interpretations and presence of molecular and other types of evidence.
Technically aren't we all just fish if you go back far enough on the evolutionary timeline?
A domestic dog, wolf and coyote can all breed together and all produce fertile offspring. Then you look at genetic variation between the three species.
I see regularly comments along those lines on the Internet. I’d like some examples of “unpublishable scientific theories” that are not obviously bunk, as opposed to just controversial. Otherwise it is mostly a convenient bogeyman for bunk mongers.
Also, replicability seems a strange concern for this field. We’re never going to have an Earth Mk2 to test hypotheses.
https://quillette.com/2018/09/07/academic-activists-send-a-p...
To stay on topic, this is not an example of career-ending article, because he’s already retired, and nevertheless still affiliated with both Georgia Tech and California Polytechnic State University. He also himself says that the un-acceptance of his article is unprecedented, so this is hardly representative of anything.
Piddling about the taxonomy of extinct species isn't problematic, but I could see a mob misinterpret this as him saying that not all living humans belong to the same species, and go on a witch hunt over the misunderstanding.
However, if some evidence started emerging that modern humans were not all the same species (whatever that actually means in practice) then I think the above comment applies. No one with a reputation to protect would touch that bit of truth with a ten foot pole.
The website also has similar articles, for example "How Human Are We?":
https://www.sapiens.org/biology/evolution-human-identity/
I like to think that if he hadn't died so young his personal tastes might have matured.
The NYT opinion article that popularized the term said:
> Affirmative action is politically correct. So too are women's studies, gay and lesbian studies, and African-American studies, all of which are strongly represented in the scholarly panels at such professional meetings as those of the American Historical Association and the Modern Language Association. [...] Biodegradable garbage bags get the p.c. seal of approval. Exxon does not.
And Bush Sr. gave a speech shortly thereafter decrying it:
> The notion of political correctness has ignited controversy across the land. And although the movement arises from the laudable desire to sweep away the debris of racism and sexism and hatred, it replaces old prejudice with new ones.
They and all the other media figures and conservative politicians and so forth in the early '90s would have all looked at you confused if you claimed that racism and sexism, themselves, were forms of political correctness.
If your argument is that public pressure to conform to racist and sexist cultural consensuses was bad for scientific research, it does not actually help the cause to defend opponents of "political correctness" who advocate for the freedom to express now-unpopular racist and sexist viewpoints.
My argument is that public pressure to conform to the political norms for its time is always bad for scientific research, regardless what the political norms are. The political norms are what is called "politically correct", things that you should believe because otherwise society will become hostile against you.
Political correct pressure on science is similar to banning all smoking health research that isn't funded by tobacco companies. Sure tobacco funded research is still research, but it will be extremely biased. The same about politically pressured research. The pressure to confirm racist ideas lead to a lot of bad science in the past. The pressure to confirm modern political ideas lead to a lot of bad science today. Those two works in exactly the same way. However since I live today and not in the past I care about the problems science face today rather than the problems it had a long time ago that are no longer relevant.
That is, I agree with you that public pressure to conform to political norms is bad for scientific research, but I am arguing that a specific focus on avoiding "political correctness" means that you in fact succumb to a lot of other (present-day) political norms, which is the actual thing that is bad for scientific research.
Taking your tobacco-funding example - you are, of course, correct, that tobacco-funded research is extremely biased. Suppose someone says that this research cannot be taken at face value, and Philip Morris accuses that person of anti-tobacco bias, of succumbing to anti-cigarette political correctness, of conforming to political pressures about how terrible Big Tobacco is. Who do you side with? There are two accusations of bias here; how you do determine which one is correct?
The heuristic "Political correctness is bad" is clearly unhelpful in this scenario; it cannot guide you to the correct decision. If you want a more meaningful principle, you have to look deeper at things. Even your phrasing "conform to the political norms for its time" is a more meaningful phrasing - but then an obvious consequence is that opposition to political correctness was the political norm of the early '90s when the president and the Gray Lady were telling people how bad political correctness was.
Right, this is a really hard topic. I didn't say I had a solution, just saying it is a problem. There will always be a lot of political influence in research topic related to controversial things and people living under that influence will have a hard time identifying it. The racists 70 years ago probably didn't think they were doing anything bad etc. But today we recognize it as bad.
> but I am arguing that a specific focus on avoiding "political correctness" means that you in fact succumb to a lot of other (present-day) political norms, which is the actual thing that is bad for scientific research.
Yeah, you have counter movements and resistances. But if the context is non-stem non-economic researchers at universities then it is pretty much only in one direction. There is no allowance for the other side to do much research in those areas, meaning research in those areas is a one sided politically correct story.
If we let tobacco companies publish research, and other people publish research, then people can look at the two and make their own decisions. But if you basically only let one side research then you will get bad research.
> Political Correctness- the avoidance, often considered as taken to extremes, of forms of expression or action that are perceived to exclude, marginalize, or insult groups of people who are socially disadvantaged or discriminated against.
> In 1934, The New York Times reported that Nazi Germany was granting reporting permits "only to pure 'Aryans' whose opinions are politically correct".[2]
The definition you read there is just what is politically correct today, it isn't what the term really means. Racism was politically correct back then, it isn't politically correct today.
https://en.wikipedia.org/wiki/Political_correctness#Early-to...
> the avoidance, often considered as taken to extremes, of forms of expression or action that are perceived to exclude, marginalize, or insult groups of people who are socially disadvantaged or discriminated against.
Aren't you taking an arbitrary definition (un-sourced from google/Oxford Language) to win your argument?
Here is Merriam-Webster's
> conforming to a belief that language and practices which could offend political sensibilities (as in matters of sex or race) should be eliminated
Seems like both are acceptable modern-day usages... like other terms a difference between capital vs lowercase might help here like... "republican" vs "Republican", "democrat" vs "Democrat"
I can understand the hesitancy to do so but I think most people, including scientists, are not aware of the likely cost. It is possibly to classify humans into races/subspecies without resorting to racial discrimination or animus - the same way we currently celebrate so called diversity.
I do believe it would likely have implications for the interventions which certain pockets of our society are attempting to install to correct for racially correlated inequities.
> Sex Redefined: The Idea of 2 Sexes Is Overly Simplistic
> Biologists now think there is a larger spectrum than just binary female and male
> “My feeling is that since there is not one biological parameter that takes over every other parameter, at the end of the day, gender identity seems to be the most reasonable parameter,” says Vilain. In other words, if you want to know whether someone is male or female, it may be best just to ask.
https://www.scientificamerican.com/article/sex-redefined-the...
But if we did, would these traits ever go away? Would human evolution eventually "revert" us back to our present form? Because something tells me that we wouldn't, and the selection process would basically say "good enough". In other words, the reason we don't look like Asari or Twi'leks is probably pure luck, and the reason alien species may look the way they do (again, if they exist) is also pure luck. But they probably share some of the general characteristics of humanoids, such as limbs not necessary for motion and with opposable fingers, a head separate from the rest of the body, etc.
TV uses humanoid aliens because they're easy to cast :)
Just look at the other intelligent life on Earth. Some birds, whales, elephants are near the top. If we hadn't nearly wiped elephants out maybe in another 10 million years they'd be making spaceships with their trunks (which have a fine manipulation ability approaching the human hand).
A little further away evolutionarily, jellyfish are remarkably intelligent and seem to even have individual personalities, and they don't have a brain.
Novelists had no such restrictions, so Larry Niven could create Pierson’s Puppeteers in 1966:
https://en.wikipedia.org/wiki/Pierson%27s_Puppeteers
They're different from humans, but much closer than we expect: mammals (apart from the birds, sure), with similar skeletal structure, similar overall "how it works" biology (brains, skeleton, digestive system, circulatory system, etc)
The closest "intelligent alien" we know of is the octopus. That's really something else. But even then a lot of biology is shared.
If you want to get creative don't think of humans mating neanderthals, think animals re-evolving from an earthworm or a jellyfish.
Great question. I enjoyed Andy Weir's take on this in his most recent book Project Hail Mary. If anyone hasn't read it yet and they're intrigued, I would suggest picking it up without finding out any more about it.
You ever start a refactor, find some dead code, and realize you could work it into a new feature? I wonder if vestigial organs are ever reused like that.
I mean, we share 90% of our DNA with mice, and 70% with worms.
Basically it could look like a smooth, slender, big-headed human but under the hood have much less in common with us than an earthworm does.
alien life may be so different from what we are familiar with ... that we may not even recognize it as life when we encounter it first
the differences may be in sheer size of the organism -- think licens and moss at planetary scale -- or even loosely collected soup or vapors of chemicals
the difference could be in metabolism that we may need 4-5 generations of humans to see them live and grow and die -- or they might live for only a fraction of a second
just like there are billions of microbes living in each of our bodies (and they have no mental capacity to comprehend us or our world) ... we may in-turn be microbes inside a much grander macro-cosm that we can never wrap our heads around
I would hardly classify these as radically different. Hutts have two arms, two eyes a nose and a mouth, and vocalize similarly to humans. Krogans are very much humanoid as well and follow the same basic body plan.
I'd agree about the Hanars. Better examples of radically different would be the Dwellers from the Algebraist, the Tines from A Fire Upon the Deep, or Alex Ries' Birrin[1]. Even then, they are all relatively human-like in their culture.
[1]: http://abiogenisis.deviantart.com/
https://www.goodreads.com/book/show/40910274-the-deep-histor...
https://www.goodreads.com/book/show/28116739-other-minds
Now you talk of aliens breathing and eating meat which can be conceived but... what of a pure liquid helium planet ? The intelligence there might be completely different, with reproduction cycles we cant imagine and energy transformation that may not even require eating other life form like us.
Same with any morphological traits, I reckon (I am not an evolutionary biologist).
"Meat?"
https://www.mit.edu/people/dpolicar/writing/prose/text/think...
> Please note that this article includes images of human remains.
I don't think I've ever seen a warning like this before in any anthropological publication, or even in a museum or exhibit. I can't say I've ever found looking at skulls to be particularly weird or shocking, especially if they are extremely old. But, is this a warning that people or the general populace are requesting or feel is necessary? Or, is it purely an editorial decision?
I went to the Carnegie Museums in Pittsburgh a couple of weeks ago, and they had warnings for if an exhibit had human remains in them (even if they were not visible, I.e. in a mummy).
They also had a short blurb on the ethics of displaying human remains, especially if the remains on exhibit didn't/couldn't give consent. I found it very thought provoking honestly.
To extend it, I found it interesting that there was a lot of discussion on the ethics of showing human remains (taxidermy, in alcohol solution, bones, etc.), but then they showed a lot of animal remains and there was no discussion on that, especially when I would assume that many of the animals shown in the museum were killed for the specific reason of having them on a museum or for study.
Edit: I wonder what is downvoteable about my original comment. My Jewish colleagues do not eat pork, but they do not avoid depictions of it, such as photos in a menu. I guess it should be similar in the case of Kohanim being forbidden to come in contact with human remains. Direct contact is very different from a painting or description.
Lazy randoms who disagree also often feel entitled that they don't have to explain their displeasure or engage in meaningful discourse. Instead, they will try to silence you for having an opinion different than theirs. Also, sometimes I think it's passive aggressive social win-lose mentality or maybe even gaslighting. Best to not care about popularity and move on seeking discussions of valuable insight rather than dwelling on being clobbered for no apparent reason.
https://www.sapiens.org/about-us/
Aboriginal Australians and Torres Strait Islanders get warnings that what they're about to view may contain depictions of people that have died. Not depictions of dead people, but depictions of people who have died since they were filmed or had their picture taken.
https://en.wikipedia.org/wiki/Australian_Aboriginal_avoidanc...
[1] What is the design behind this article called?
[2] No matter what I do in my browser settings, it seems like text is small without zooming in individual websites. I need to zoom in to 200% to be able to read it. Is this just a recent trend? https://imgur.com/a/6C2xJkG
http://stonetoss.com/comic/wagging-the-dog/