[samsartor]

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.

[ralfd]

> 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.

[masfuerte]

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.

[bilbo0s]

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.

[adrianN]

Are people of Philippine decent that are born and raised in the Netherlands statistically the same height as native Dutch?

[Mr_Minderbinder]

> 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.

[daveguy]

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.

[pfdietz]

> 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.

[daveguy]

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.

[pfdietz]

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.

[daveguy]

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.

[pegasus]

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.

[rolph]

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

[pfdietz]

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.

[cineticdaffodil]

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.