Landmark ancient-genome study shows surprise acceleration of human evolution • Hacker News Board

Re: Landmark ancient-genome study shows surprise acceleration of human evolution

#121

Post by daveguy » Sat, Apr 18, 2026, 3:55 PM UTC

pfdietz wrote: post #115

daveguy wrote: post #108

Earlier quoted context omitted.

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 i…

> 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.

Re: Landmark ancient-genome study shows surprise acceleration of human evolution

#122

Post by pfdietz » Sat, Apr 18, 2026, 4:29 PM UTC

daveguy wrote: post #121

pfdietz wrote: post #115

Earlier quoted context omitted.

> 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 av…

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.

Re: Landmark ancient-genome study shows surprise acceleration of human evolution

#123

Post by pegasus » Sat, Apr 18, 2026, 4:36 PM UTC

samsartor wrote: post #65

like_any_other wrote: post #7

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…

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.

Re: Landmark ancient-genome study shows surprise acceleration of human evolution

#124

Post by pegasus » Sat, Apr 18, 2026, 4:52 PM UTC

matt-attack wrote: post #120

greazy wrote: post #20

Earlier quoted context omitted.

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. So your question is hard to answer.

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 r…

> 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.

Re: Landmark ancient-genome study shows surprise acceleration of human evolution

#125

Post by pegasus » Sat, Apr 18, 2026, 5:00 PM UTC

greazy wrote: post #20

like_any_other wrote: post #7

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.

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. 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.

Re: Landmark ancient-genome study shows surprise acceleration of human evolution

#126

Post by scotty79 » Sat, Apr 18, 2026, 5:15 PM UTC

SloppyDrive wrote: post #39

like_any_other wrote: post #7

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.

We dont categorize humans that way; not because humans are different but because of cultural norms. 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.

I think cultural norms enforced over generations can lead to altered genetic variability.

Re: Landmark ancient-genome study shows surprise acceleration of human evolution

#127

Post by daveguy » Sat, Apr 18, 2026, 5:19 PM UTC

pfdietz wrote: post #122

daveguy wrote: post #121

Earlier quoted context omitted.

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 av…

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.

Re: Landmark ancient-genome study shows surprise acceleration of human evolution

#128

Post by vintermann » Sat, Apr 18, 2026, 5:44 PM UTC

verisimi wrote: post #63

SloppyDrive wrote: post #39

Earlier quoted context omitted.

We dont categorize humans that way; not because humans are different but because of cultural norms. 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.

I agree - cultural educating trumps scientific definitions.

Science, or you, can make up whatever definitions they wish. The question is not if a definition is "true", but what it's useful for.

Sure, you - or scientific authorities, whoever they might be - can declare that there are multiple modern human species. The question is, what are you intending to use that definition for?

That applies to other branches of the tree of life, too. There's not some objective genetic distance measure which says what's a species and what is not. It can vary widely on different parts of the tree. But it's driven by pragmatism - sensible biologists will not waste time arguing whether some mushrooms should be one species or two, if they otherwise agree on the facts.

If you can't say plainly and clearly what the purpose of your delineation is, and it's in your own part of the tree, of course people are going to have their suspicions.

Re: Landmark ancient-genome study shows surprise acceleration of human evolution

#129

Post by rolph » Sat, Apr 18, 2026, 5:47 PM UTC

pegasus wrote: post #123

samsartor wrote: post #65

Earlier quoted context omitted.

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…

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 ev…

you want to be a little careful.

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

Re: Landmark ancient-genome study shows surprise acceleration of human evolution

#130

Post by vintermann » Sat, Apr 18, 2026, 5:53 PM UTC

MontyCarloHall wrote: post #37

AlotOfReading wrote: post #29

Earlier quoted context omitted.

It's unfortunate that the URL happens to be buzzfeed, but there was an open letter to Reich by other academics about his terminology in the book you're quoting [0]. The short of it is that social categorizations we believe in like race intersect with genetics in a very complicated way. Reich is a world-class expert in genetics. He simply commits the same error as many other other experts in discounting the complexity…

The crux of that letter is the "need to recognize that meaningful patterns of genetic and biological variation exist in our species that are not racial." This is true. However, this does not mean that there aren't also meaningful patterns of genetic and biological variation that do stratify according to ancestry (not race!). The letter tries to handwave this away, claiming that "[f]or several decades billions of doll…

> "need to recognize that meaningful patterns of genetic and biological variation exist in our species that are not racial." This is true.

There's an implicit assertion in that statement, that we're currently not recognizing that meaningful patterns and variation exists. But that's nonsense. We are all perfectly aware that some groups digest lactose better, some are less vulnerable to skin cancer, some drop like flies to common tropical diseases, some completely dominate long distance running competition etc.

So there's got to be some particular differences he's referring to that he thinks are papered over. He should spell out which.