Is there any species, other than humans, that is found all across the globe (i.e. geographically separated), and has not differentiated into subspecies? Wolves, elephants, tigers, bears, and foxes have all been categorized into multiple subspecies each, distinct but able to interbreed.
My understanding is that humans have very limited genetic diversity compared to most other animals, because of the population bottlenecks we've been through. And further, that diversity is mostly between individuals, not between groups. The distinction is easy to see in cats vs dogs: they both have similar overall genetic diversity but two Chihuahuas have virtually all the same genes (the small angry ones) while two tabby cats are more distinct. The two cats have different combinations of big/small nice/mean smart/dumb, but the genes average out to the same "typical" kind of cat in both cases.
Because humans get around so much, and because we think interesting-looking people are hot, the diversity is spread pretty broadly across the whole population. The average european person and the average east asian person are a little bit different genetically, but way less different than any two real europeans or two east-asians are to one another.
In short, the distributions of individuals overlap so much that the trendlines are pretty close to useless. And historically speaking, the people who tried to make a hard distinction out of those trendlines had awful motives.
> The average european person and the average east asian person are a little bit different genetically, but way less different than any two real europeans or two east-asians are to one another.
This is always touted as an “racism-is-not-only-immoral-it-is-scientifically-wrong” argument, but it is a fallacy.
Example: The average height (a trait with very high heritability) of Dutch men is 6’0 feet (183 cm) and the average height of Philippine men is 5’4 (163 cm). This means the height difference between these two groups is 20 cm. And it is obvious that the difference inside one group MUST be larger, for example there are 6’4 Dutch basketballers but also certainly Dutch 5’2 horse riding jockeys.
And depending on context both of these insights are useful. For example if you manage a basketball team it is much more effective to consider people as individuals, simplified you should hire very tall people (regardless if they are Dutch or Philippines) who can throw precisely a ball into a basket. But the diversity between population groups points to real information too! If you sell shoes to both countries you shouldn’t provide the same one-size-fits-all and assume to catch the same percentage of the market.
Plus the overlap in one metric is expanding into separable clusters the more dimensions are used:
Take a Dutch and Philippine who have the exact same height: Their own respective brothers (heck, even twins) will not be the same perfect match, instead being a bit taller or smaller. But the more variables you consider (weight, muscle composition, leg length, head radius, hand size, form of earlobe .. etc) you will find that holistically seen two brothers truly are much more similar to each other than to a stranger.
A few hundred years ago Europeans were very much shorter too. The Chinese have increased in height within just the last couple of generations. In both cases this isn't because their genes changed, it's because their diets changed. Diet also explains the difference between the Netherlands and the Philippines.
The height thing is a bad example. Generally in genetics you like to focus on things without so many confounding factors. That's why the article focuses on attributes like baldness, MS, and lactose intolerance.
> Example: The average height (a trait with very high heritability) of Dutch men is...
I would not give too much credence to the various figures often given for the average height of men and women in x country without careful research, since they have highly variable degrees of support.
For years I had heard repeatedly that the average height of a man in Indonesia was 158 cm or 5ft and 2 inches. This seemed so absurd to me and provoked enough scepticism that I eventually attempted to track down the source of that figure. It turned out to be from Wikipedia and the citation was a study that measured the heights of the elderly yet all of those repeating that figure neglected to mention, or were in all likelihood entirely ignorant of, that detail. I am similarly sceptical of some of the claims made about the average height of the Dutch, the subject of which seems to be a particular favourite among height myth-mongers.
With respect to young adult men I have found that figures based on measurements obtained as part of fitness screenings for mandatory military service are the most reliable due to their large sample size (at least an order of magnitude larger than the largest academic studies) and overwhelming lack of selection and sampling bias. A minority of nations have such systems and fewer still publish the data obtained in public. Yet even this would not answer the question for the whole population.
None of what you said refutes the fact that genetic diversity is just as different within two people of the same ethnicity as it is between different ethnicities.
You listed a handful of traits from a handful of genes. And from that you make an argument about relative distributions of entire genomes of entire populations. Do you realize the fact that brothers are genetically similar compared to a stranger in no way implies the similarity or difference of entire populations?
Even the traits you mention are just a handful of physical traits. There are about 20,000 protein encoding genes and 180,000 non-encoding. Protein encoding genes code for the structures in our body. The other 180,000 genes code for all kind of dynamics -- the rna that turns genes to proteins, how proteins are expressed in different cells to make them different cells, how relative expression levels change in response to external stimulus, etc. So, the set of genes to consider is clearly all 200,000 genes and not just the 20,000 protein encoding genes much less the handful of protein encoding genes responsible for something like eye color.
Unfortunately for racists but fortunately for the vast majority, the world is a great big melting pot with all the different ethnicities producing all kinds of variety. So much that the blend complexity long ago surpassed any tiny set of visible trait uniformity.
I honestly don't know how so many people fall for these simplistic illogical racist arguments. But it makes me happy to know that racists are about 200,000 years to late to shove the entire human race into tiny little boxes based on physical traits.
> None of what you said refutes the fact that genetic diversity is just as different within two people of the same ethnicity as it is between different ethnicities.
Note, however, that this does not imply there are not significant genetic differences between different ethnicities. Differences that are selected for will be cloaked in a sea of non-significant differences.
Definitely. I'm not saying there aren't average differences. We literally see different physical traits. But physical traits are a minute fraction of all the complexity that is the human genome. And all of those physical traits are always mixing fluidly between and within groups.
My point is, there are clearly wide swaths of genetic traits that we have in common with any other ethnicity compared to what may be the average of a broad distribution. Humans are inherently mosaic.
Personally I believe it's why our species is so resilient. But that's a stronger statement, so just a belief.
Yes, and there are also wide swaths of genetic traits that we have in common with other species. But it would be senseless to propose we're the same as chimpanzees. The point is it doesn't take much in the way of genetic differences, as a fraction of the total genome, to make a very large difference in phenotype.
Well, if the phenotype or trait due to any random gene was the differentiation between race, species, or anything else besides that specific trait, you might have a point in support of OP. But unfortunately for racist ducks there are so many differences, and similarities, that have nothing to do with hair color or height. Any given swath is it's own mosaic of combinations, no matter what we label it.
I read what you wrote there several times and can't make heads or tails of what you're trying to say. Are you claiming genetic differences aren't why species are different? Are you claiming chimps and humans don't share most of their (protein coding) genes? Are you attacking a strawman where you think the people you are attacking are claiming specific single gene differences are why they claim races are genetically different?
I'll add that "racist ducks" is a bad sign there, since arguments about facts don't have anything to do with motivation, and bringing up motivation is an ad hominem argument. "Argue like this and you are a bad person."
Good points. On the bottleneck hypothesis, a new study came out in 2024 arguing that the 900kya population loss was, if not a statistical artifact, more likely a genetic sweep or genome takeover via adaptive advantage. Whatever might be the truth in this case, it is true that human evolution, especially on the cultural plane, has gone through a bunch of major leaps which have had the effect of one small population eventually dominating the global genetic pool. Basically, a winner-takes-all dynamic. One example would be the Proto Indo-Europeans who have replaced male lineages throughout Europe and beyond. There are other such examples as well, like Neanderthal extinction.
genetic bottleneck does not imply population loss.
it is about unavailability of large gene pool.
this can be population loss, but can also, be a loss of compatability between individuals, due to genomic modification, such as but not limited to chromosomal fusion.
However, with a population of 8 billion and a genome of 3.1 billion base pairs, the entire space of single nucleotide mutations is produced in just a few generations. So any such useful single nucleotide mutation is going to become available regardless of past bottlenecks.
I ve read this in a breathless ("help my ideology is under attack by reality") voice and it took a page away fro interesting discussions.
My pet theory is that the species inherited a loop deformation by default from our ancestors, defacto splitting the species planetwide into three subspecieses. One adapted to peace, one adapted to strife, one adapted to all out carnage. The obvious benefits of various adaptions of what we perceive as mental sickness, but what are actual adaptions to the loop communicating themselves. In this small moment where one (peacetime) insanity is uprooted to replace with a (wartime) insanity, might we be free in the anti gravity of the situation to discuss complex answers before the yikes of you silence us for the rest of the cycle? Thanks for the gag in all these years, that helped and did nothing.
The definition of what constitutes a species is a human construct.
Two bird populations living in the same locale but divided by a mountain range therefore not naturally breeding with each other would classify as a different species, even if they could breed with each other.
> The definition of what constitutes a species is a human construct
That makes it sound like the boundaries between species are arbitrary, but they are not. Sure, there are corner cases where things become debatable, but those are the rare exceptions, not the rule.
> Two bird populations living in the same locale but divided by a mountain range therefore not naturally breeding with each other would classify as a different species, even if they could breed with each other.
This is only the case if the separation has been there long enough for the two groups to develop distinct genetic markers or physical traits (like the beak shape or plumage mentioned in the original comment). The deeper reason they are classified as different species it that they are de-facto on different evolutionary trajectories. Which doesn't happen for human populations because historically, whatever obstacle divide us, we find a way to get around it.
Seems to me, that we divide other animals based on some of the most minor of phenotypic expressions. The slight coloration of a bird’s crest, shape of some lizard’s nose.
Yet with Homo sapiens we seem to be allergic to the idea that our drastic swings in physical attributes could possibly qualify as a different species (we obviously call them “races”). But they plainly diverged from each other due to geographic and reproductive isolation and adaptation to environments. Which is precisely what causes species to diverge into new ones.
Are we supposed to pretend that Africans DONT have black skin due an adaptation to their environment?
Do other animals get divided into races? I know dogs have “breeds” and we don’t consider those species. But I don’t hear about “races” in other animals.
> Seems to me, that we divide other animals based on some of the most minor of phenotypic expressions
It might seem like that to you, but you'd be wrong. Taxonomy prioritizes genetic distance and reproductive isolation over superficial visual traits that humans happen to find striking. While phenotypic variations like skin color or facial structure are highly visible, they represent a microscopic fraction of the overall genome and do not indicate the deep divergence required to define a new species.
And from a genetic standpoint, Homo sapiens is remarkably homogeneous. Two humans from opposite sides of the planet are generally more genetically similar to each other than two chimpanzees from the same patch of forest. Traits like skin color (an adaptation for UV protection) or nose shape (an adaptation for humidity/temperature) are rapid evolutionary adjustments. They change quickly on an evolutionary timescale without requiring a fundamental split in the species' lineage.
In contrast to other animals, because humans never stopped breeding with one another, we never had the chance to "drift" far enough apart to become different species. Geographic distance in humans has historically acted as a filter, not a wall.
So there's your answer. Because of this unique genetic homogeneity (and not because of some imagined woke censorship), speaking of human subspecies would be scientifically mistaken.
> Two bird populations living in the same locale but divided by a mountain range therefore not naturally breeding with each other would classify as a different species, even if they could breed with each other.
Really? I thought the requirements for species classification were: (1) must be able to reproduce and (2) offspring must be fertile.
my understanding of what classifies something as being a part of the same species is the fact that they can make children that are viable to have children themselves
horses and donkeys can breed to make mules, but the mules usually cant reproduce, this is the same with tigons and ligers but sometimes the females are viable
so if they can produce children that can produce children, they're the same species. where this line is blurred, so is the species line. geographical barriers have nothing to do with it.
Not many. Part of why we are like this is extreme mobility. Even before modern times we were always good at getting around and seem to have a desire to roam. Or at least enough of us do to mix up those gene pools.
Do humans not fit the standards for being broken into multiple subspecies? I assumed that they would but "the science community" is too scared of the implications when idiots learn about it.
I look at a sumatran tiger and a Siberian tiger and I see a lot less variance than I see when I look at
a pygmy, a Norwegian, an sentinel islander, and a han Chinese person
Many researchers now refer to neanderthals as Homo sapiens neanderthalensis, a subspecies of modern humans.
It doesn’t get talked about much because it’s a sideshow without an easy resolution, but the question of modern and archaic human speciation is far from a settled problem and many of the species formerly considered to be separate are now often lumped in as subspecies.
So have humans. There are white, red, black, brown, yellow people, and they live in their own happy places on the planet, except for the fact that we now move them around by plane, boat and goat.
I mean people won't like the idea but that's not my point; what you describe variety in superficial traits while maintaining common traits
Applied to humans; skin color, eyes, dwarfism, hypertrichosis... can still interbreed
When it comes to categorization and taxonomy in leaky abstractions like languages the boundaries get a bit hand wavy and usually land on whatever fits the prevailing social desirability bias of the day
It seemed unlikely that ancestral populations had so many physiological differences, but not cognition. This seems like the last piece to compliment observed IQ differences between groups and levels of civilizational attainment.
Every time I read about ancient DNA work, it's about Reich's research. Can anyone expert in the field shed light on that? He certainly seems to have a successful research group. And he's a good communicator, I got a lot out of his 2018 book. Who else should I be reading or reading about?
Not that surprising when you consider, as the paper does, the explosion of very meaningful traits such as the ability to digest lactose and various anti-malaria adaptations e.g. Sickle Cell and the Duffy-null mutation.
It's just controversial for obvious reasons. The notion that human groups may have meaningfully evolved in different ways over the past 10,000 years, and may still be evolving, is an unpopular one on both ends of the political spectrum.
funny how racists on twitter havent learnt that skin color is a function of natural selection, how do we get this message to them in a non offensive yet informational enough way to change their perceptions of colored people
We finally observed signals of selection for combinations of alleles that today are associated with three correlated behavioural traits: scores on intelligence tests (increasing 0.74±0.12), household income (increasing 1.12±0.12) and years of schooling (increasing 0.63±0.13). These signals are all highly polygenic, and we have to drop 449–1,056 loci for the signals to become non-significant(Extended Data Fig.10). The signals are largely driven by selection before approximately 2,000 years , after which tends towards zero.
That's the part that the speech police is afraid of.
"To supercharge the search, Reich, Ali Akbari, a computational geneticist at Harvard Medical School, and their colleagues amassed the largest-ever collection of genomic data from ancient humans — from a total of 15,836 individuals from western Eurasia — including more than 10,000 newly sequenced genomes."
Without commenting on the content of this sentence or article, I will say that it is refreshing to see sentences like this in the wild after being regularly and constantly subjected to LLM slop.
166 comments
Because humans get around so much, and because we think interesting-looking people are hot, the diversity is spread pretty broadly across the whole population. The average european person and the average east asian person are a little bit different genetically, but way less different than any two real europeans or two east-asians are to one another.
In short, the distributions of individuals overlap so much that the trendlines are pretty close to useless. And historically speaking, the people who tried to make a hard distinction out of those trendlines had awful motives.
> The average european person and the average east asian person are a little bit different genetically, but way less different than any two real europeans or two east-asians are to one another.
This is always touted as an “racism-is-not-only-immoral-it-is-scientifically-wrong” argument, but it is a fallacy.
Example: The average height (a trait with very high heritability) of Dutch men is 6’0 feet (183 cm) and the average height of Philippine men is 5’4 (163 cm). This means the height difference between these two groups is 20 cm. And it is obvious that the difference inside one group MUST be larger, for example there are 6’4 Dutch basketballers but also certainly Dutch 5’2 horse riding jockeys.
And depending on context both of these insights are useful. For example if you manage a basketball team it is much more effective to consider people as individuals, simplified you should hire very tall people (regardless if they are Dutch or Philippines) who can throw precisely a ball into a basket. But the diversity between population groups points to real information too! If you sell shoes to both countries you shouldn’t provide the same one-size-fits-all and assume to catch the same percentage of the market.
Plus the overlap in one metric is expanding into separable clusters the more dimensions are used:
https://i.sstatic.net/r6cWd.jpg
Take a Dutch and Philippine who have the exact same height: Their own respective brothers (heck, even twins) will not be the same perfect match, instead being a bit taller or smaller. But the more variables you consider (weight, muscle composition, leg length, head radius, hand size, form of earlobe .. etc) you will find that holistically seen two brothers truly are much more similar to each other than to a stranger.
> Example: The average height (a trait with very high heritability) of Dutch men is...
I would not give too much credence to the various figures often given for the average height of men and women in x country without careful research, since they have highly variable degrees of support.
For years I had heard repeatedly that the average height of a man in Indonesia was 158 cm or 5ft and 2 inches. This seemed so absurd to me and provoked enough scepticism that I eventually attempted to track down the source of that figure. It turned out to be from Wikipedia and the citation was a study that measured the heights of the elderly yet all of those repeating that figure neglected to mention, or were in all likelihood entirely ignorant of, that detail. I am similarly sceptical of some of the claims made about the average height of the Dutch, the subject of which seems to be a particular favourite among height myth-mongers.
With respect to young adult men I have found that figures based on measurements obtained as part of fitness screenings for mandatory military service are the most reliable due to their large sample size (at least an order of magnitude larger than the largest academic studies) and overwhelming lack of selection and sampling bias. A minority of nations have such systems and fewer still publish the data obtained in public. Yet even this would not answer the question for the whole population.
You listed a handful of traits from a handful of genes. And from that you make an argument about relative distributions of entire genomes of entire populations. Do you realize the fact that brothers are genetically similar compared to a stranger in no way implies the similarity or difference of entire populations?
Even the traits you mention are just a handful of physical traits. There are about 20,000 protein encoding genes and 180,000 non-encoding. Protein encoding genes code for the structures in our body. The other 180,000 genes code for all kind of dynamics -- the rna that turns genes to proteins, how proteins are expressed in different cells to make them different cells, how relative expression levels change in response to external stimulus, etc. So, the set of genes to consider is clearly all 200,000 genes and not just the 20,000 protein encoding genes much less the handful of protein encoding genes responsible for something like eye color.
Unfortunately for racists but fortunately for the vast majority, the world is a great big melting pot with all the different ethnicities producing all kinds of variety. So much that the blend complexity long ago surpassed any tiny set of visible trait uniformity.
I honestly don't know how so many people fall for these simplistic illogical racist arguments. But it makes me happy to know that racists are about 200,000 years to late to shove the entire human race into tiny little boxes based on physical traits.
> None of what you said refutes the fact that genetic diversity is just as different within two people of the same ethnicity as it is between different ethnicities.
Note, however, that this does not imply there are not significant genetic differences between different ethnicities. Differences that are selected for will be cloaked in a sea of non-significant differences.
My point is, there are clearly wide swaths of genetic traits that we have in common with any other ethnicity compared to what may be the average of a broad distribution. Humans are inherently mosaic.
Personally I believe it's why our species is so resilient. But that's a stronger statement, so just a belief.
I'll add that "racist ducks" is a bad sign there, since arguments about facts don't have anything to do with motivation, and bringing up motivation is an ad hominem argument. "Argue like this and you are a bad person."
genetic bottleneck does not imply population loss.
it is about unavailability of large gene pool.
this can be population loss, but can also, be a loss of compatability between individuals, due to genomic modification, such as but not limited to chromosomal fusion.
https://www.johnhawks.net/p/when-did-human-chromosome-2-fuse
https://en.wikipedia.org/wiki/Robertsonian_translocation
My pet theory is that the species inherited a loop deformation by default from our ancestors, defacto splitting the species planetwide into three subspecieses. One adapted to peace, one adapted to strife, one adapted to all out carnage. The obvious benefits of various adaptions of what we perceive as mental sickness, but what are actual adaptions to the loop communicating themselves. In this small moment where one (peacetime) insanity is uprooted to replace with a (wartime) insanity, might we be free in the anti gravity of the situation to discuss complex answers before the yikes of you silence us for the rest of the cycle? Thanks for the gag in all these years, that helped and did nothing.
Two bird populations living in the same locale but divided by a mountain range therefore not naturally breeding with each other would classify as a different species, even if they could breed with each other.
So your question is hard to answer.
> The definition of what constitutes a species is a human construct
That makes it sound like the boundaries between species are arbitrary, but they are not. Sure, there are corner cases where things become debatable, but those are the rare exceptions, not the rule.
> Two bird populations living in the same locale but divided by a mountain range therefore not naturally breeding with each other would classify as a different species, even if they could breed with each other.
This is only the case if the separation has been there long enough for the two groups to develop distinct genetic markers or physical traits (like the beak shape or plumage mentioned in the original comment). The deeper reason they are classified as different species it that they are de-facto on different evolutionary trajectories. Which doesn't happen for human populations because historically, whatever obstacle divide us, we find a way to get around it.
Yet with Homo sapiens we seem to be allergic to the idea that our drastic swings in physical attributes could possibly qualify as a different species (we obviously call them “races”). But they plainly diverged from each other due to geographic and reproductive isolation and adaptation to environments. Which is precisely what causes species to diverge into new ones.
Are we supposed to pretend that Africans DONT have black skin due an adaptation to their environment?
Do other animals get divided into races? I know dogs have “breeds” and we don’t consider those species. But I don’t hear about “races” in other animals.
> Seems to me, that we divide other animals based on some of the most minor of phenotypic expressions
It might seem like that to you, but you'd be wrong. Taxonomy prioritizes genetic distance and reproductive isolation over superficial visual traits that humans happen to find striking. While phenotypic variations like skin color or facial structure are highly visible, they represent a microscopic fraction of the overall genome and do not indicate the deep divergence required to define a new species.
And from a genetic standpoint, Homo sapiens is remarkably homogeneous. Two humans from opposite sides of the planet are generally more genetically similar to each other than two chimpanzees from the same patch of forest. Traits like skin color (an adaptation for UV protection) or nose shape (an adaptation for humidity/temperature) are rapid evolutionary adjustments. They change quickly on an evolutionary timescale without requiring a fundamental split in the species' lineage.
In contrast to other animals, because humans never stopped breeding with one another, we never had the chance to "drift" far enough apart to become different species. Geographic distance in humans has historically acted as a filter, not a wall.
So there's your answer. Because of this unique genetic homogeneity (and not because of some imagined woke censorship), speaking of human subspecies would be scientifically mistaken.
Take for example: Icterus gularis [1] vs Icterus galbula [2]
Are you really going to tell me that:
1. They’d refuse to have sex with each other or could not procreate
And:
2. Someone bothered to check if they’re sufficiently distinct genetically?
I suspect these species were deemed “distinct” by early naturalists like Carl Linnaeus or Charles Darwin neither of whom even knew what a gene was.
And to my eye these birds seem a lot closer than an Aboriginal Australian man is to a Norwegian man.
[1] https://en.wikipedia.org/wiki/Altamira_oriole
[2] https://en.wikipedia.org/wiki/Baltimore_oriole
> Two bird populations living in the same locale but divided by a mountain range therefore not naturally breeding with each other would classify as a different species, even if they could breed with each other.
Really? I thought the requirements for species classification were: (1) must be able to reproduce and (2) offspring must be fertile.
Is it less objective than that?
horses and donkeys can breed to make mules, but the mules usually cant reproduce, this is the same with tigons and ligers but sometimes the females are viable
so if they can produce children that can produce children, they're the same species. where this line is blurred, so is the species line. geographical barriers have nothing to do with it.
speciation is reproductive incompatability.
geographic isolation is more like founder effect than speciation.
I look at a sumatran tiger and a Siberian tiger and I see a lot less variance than I see when I look at a pygmy, a Norwegian, an sentinel islander, and a han Chinese person
It doesn’t get talked about much because it’s a sideshow without an easy resolution, but the question of modern and archaic human speciation is far from a settled problem and many of the species formerly considered to be separate are now often lumped in as subspecies.
It’s not quite all across the globe but pretty close, and is so adapted that it is not considered invasive any more in most places.
> ...distinct but able to interbreed
I mean people won't like the idea but that's not my point; what you describe variety in superficial traits while maintaining common traits
Applied to humans; skin color, eyes, dwarfism, hypertrichosis... can still interbreed
When it comes to categorization and taxonomy in leaky abstractions like languages the boundaries get a bit hand wavy and usually land on whatever fits the prevailing social desirability bias of the day
The generous idea is that "subspecies" does not provide an anthropologist a useful lens to look at humanity, therefore we do not classify.
The alternative is that "subspecies" is too close to "race" for scientists, publishers, and funding bodies to touch, so its deliberately ignored.
It's just controversial for obvious reasons. The notion that human groups may have meaningfully evolved in different ways over the past 10,000 years, and may still be evolving, is an unpopular one on both ends of the political spectrum.
We finally observed signals of selection for combinations of alleles that today are associated with three correlated behavioural traits: scores on intelligence tests (increasing 0.74±0.12), household income (increasing 1.12±0.12) and years of schooling (increasing 0.63±0.13). These signals are all highly polygenic, and we have to drop 449–1,056 loci for the signals to become non-significant(Extended Data Fig.10). The signals are largely driven by selection before approximately 2,000 years , after which tends towards zero.
That's the part that the speech police is afraid of.
Without commenting on the content of this sentence or article, I will say that it is refreshing to see sentences like this in the wild after being regularly and constantly subjected to LLM slop.