Self-reported race, ethnicity don't match genetic ancestry in the U.S.: study

It's harder now because now you live in America and are used to seeing all these people as Americans, and then as members of whatever racial consciousness we have in America.

Back in those respective countries, they can tell everyone apart. When my wife (Irish/English by ancestry) visited Hungary, they were immediately able to peg her as a foreigner, and frankly, so was I. They look nothing alike aside from skin color. This is true of basically any country in Europe, Africa, Asia, where people have tended to remain in the same location for thousands of years.

I think even most Americans would be able to tell apart African and European races if they really tried.

[flagged]

The point is that race is a bad proxy for ethnicity. We should expect the environmental factors to also mirror ethnic clustering.

It’s still correlated enough with ancestry that it can be a useful proxy for health issues related to ancestry—in addition to the environmental factors you pointed out.

Specifically they would both be of Khoi-San ethnicity. The vast majority of humans have been through two population bottlenecks which drastically reduced the genetic diversity of the populations. Most African populations have been through at least one of these bottlenecks, and every population group outside of Africa has been through two. The Khoi-San, however, seem to have broken off prior to either of the bottlenecks and so they retained much higher genetic diversity.

Is that specifically the case? This feels like an area where our language can fail to capture the nuance of what someone is trying to say and it gets misstated as something really similar but different.

To give an example, take 3 people named A, B, and C. A and B are both from Africa, while C is from elsewhere.

A and B have 9 genetic differences. B and C have 1 genetic difference. A and C have 10 genetic differences.

We can make the claim that the genetic difference between someone from Africa and from elsewhere (B to C, thus 1) is much smaller than the difference between two people in Africa (A to B, thus 9). 1 is smaller than 9, so this statement is true, but could easily be misunderstood to saying that the two most genetically distinct individuals are from Africa, which isn't the case because A to C is the most genetically distinct and C is from elsewhere.

The two statements seem nearly equivalent and the wrong one could accidentally be spread by someone who is really just trying to focus on expressing how much genetic diversity is within Africa.

Not just as much, but it literally includes most of the genetic diversity in the rest of the world.

What lead to this?

Because of slavery, most African Americans don't know where they originated from so African American is the the most descriptive label you can get.

The effect is much larger than that. For most of the evolutionary history of humans, everyone* lived in Africa. Then only quite small groups left, taking with them only a small fraction of the genetic diversity of humans. Even today, the great majority of genetic diversity among living humans is inside Africa.

(* who mattered. There were earlier migrations of hominids, but the mark they left on our genetics is much smaller than the influence from later migrations.)

I was under the impression humans migrated from Africa so the rest of the world is all african-X, where the african- part is some subset of the original african population.

More importantly, humans have lived in Africa far longer than anywhere else in the world, so have had much more time to genetically diversify.

It's not just about size.

Humans originated in Africa, so populations there have had more time to evolve and become more diverse.

200,000 years of genetic drift versus 20,000 years makes a big difference.

Is it? What race is someone who's Arab? What about someone who could look black with one haircut but white with another? What about half-Arab, half-Euro?

This might sound like nitpicking, but most black people in the US have significant European ancestry and the admixture can vary wildly even for people with similar skin tones. Our naive view of "race" is not always backed by genetic reality.

> If race carries useful information.

It's pretty low quality information. If you're taking a genetic test you want something that returns susceptibility to sickle cell amenia, cystic fibrosis, tay-sachs, et cetera. Race is a very low quality signal that is used when you lack something better, like a genetic test.

There are zero genetic markers for race. This is because race is purely a social construct.

Very true, but of course you're talking about a different era much further up the tree.

I don’t; unless you are referring to the discredited “out of Africa” theory

How is this possible?

We use breeds for other species, like cats, dogs, horses, etc. Humans could probably be categorized by breeds —breeds of course would not parallel ‘races’ but could still subdivide our species in new ways like we do with other animal species.

[flagged]

ethnicity is what you mean. unless you are claiming, the AI's model didn't have the concept of "race" in it's training data but was able to come up with a novel classification scheme that aligns with society's concept of race.

AI confirming human bias because it was trained on it doesn't mean much.

x-rays don't measure purely innate, genetic factors, they reflect things that are influenced by nurture as well as nature (and might, in principle, even have detectable difference based on differences in how technicians treat and react to the patient.)

it's not the US alone, this concept originated from the UK. Charles Darwin's theory of evolution was used by the ruling class (think, east India company directors and such) to divide humans into sub-species with different levels of evolution. This would allow them the moral justification they needed to continue their conquest. There is a reason "all people are created equal" is the phrase used to abolish things like slavery. people focus on the "created" part, but the equal part is just as relevant.

This concept of race is designed so that one race can claim better evolution than the other, as a whole that is. People with specific ancestry might be better at specific things (provided they pursue those things to their potential), but associating that with an entire race was only useful at the time of this social constructs' creation because Europe needed to conquer the world and what do Europeans have in common the rest of the world doesn't have? Skin color. Which due to the latitude of Europe as a continent, people whose ancestors are from there have less melanin in their skin to account for lesser sunlight (You can see the same effect with north-east Asians). If you think about it, the western classification of "race" has more to do with geography than genealogy.

> the US dividing the entire world in four "races" as such: white, black, Asian, and latino.

The US government scheme has more than four top-level racial categories, and "Hispanic or Latino", in that system, is an ethnicity, not one of the races.

I don't think that's what they were arguing:

> Her statement doesn't make race any less real, but it does indicate what race IS.

Think about the probabilities. Lactose intolerance in the UK (as a proxy for British Americans) is under 10%, while in my home country it is over 85%. Meanwhile, drinking milk is universal among white American children (it’s served in schools). If a white kid has stomach problems, there’s a 90% chance it’s not lactose intolerance. But if an Asian kid presents with stomach problems, lactose intolerance is probably the single likeliest explanation. And it can be assessed by asking a couple of simple questions.

Our kids are half white so we were unsure if they’d be lactose intolerant. At the first sign of stomach problems in the youngest, we switched him to lactose free milk and the problem went away immediately. If we took him to a doctor we might’ve gone down a whole rabbit hole of dead ends. And if we weren’t aware of the issue and looking out for it, we may have not done anything and just let him deal with the discomfort. After all, kids get tummy aches for a million reasons.

He could push a bunch of buttons and draft legislation to prevent it from being used in Louisiana.

I'm sure they'll use it whenever possible, regardless of his quote.

It's a social construct in the way that all categories are. The question is whether or not a category is useful. I'm saying there are genetic differences between groups, but our structuring of these groups is pretty flexible. There are genetic differences between "continental groups" but there is also a good amount of genetic diversity within sub-Saharan Africa populations because those people did not go through the genetic bottleneck that Eurasians did.

Our understanding of race have been historically contingent. Both the racial essentialism of the colonial period and the "we are all the same under the skin" anti-racism of post-WW2 were based more on political ideologies than reality.

If you tell me you have a test that can distinguish a Japanese person from a Finn, I'd say sure. If you told me you had one that could distinguish a French person from a German, I'd laugh.

It does seem a little silly. My great-great grandfather on one side was from germany, but i don't identify as german. The link is too weak and i have no cultural connection.

The problem comes when, well, did anyone ever verify Ancestry data?

My understanding from the sidelines was that the reported ethnicity of "oh you have a little french in you" had no meaningful basis, and was absurdly inaccurate. People treating it as anything more than fiction were making a mistake.