Short Wave - Why You Can't Tell Your Race From A DNA Test

Episode Date: May 17, 2023

Race is a social construct — so why are DNA test kits like the ones from 23andMe coded like they reveal biological fact about the user's racial makeup? This episode, Short Wave Scientist in Residence Regina G. Barber talks to anthropologist Agustín Fuentes about the limits of at-home genetic tests and how misinformation about race and biology can come into play. Using science at home to decode your life? Email us at [e-mail] pcm.adswizz.com for information about our collection and use of personal data for sponsorship and to manage your podcast sponsorship preferences.NPR Privacy Policy

You're listening to Shortwave from NPR. In the year 2000, the Human Genome Project completed their first draft of the very first sequenced human genome. It was celebrated as a major breakthrough for humanity. Without a doubt, this is the most important, most wondrous map ever produced by humankind. In a speech from the White House, former President Bill Clinton touted the advancements this discovery would bring. With this profound new knowledge, humankind is on the verge of gaining immense new power to heal. And in a lot of ways, genomic data has lived up to that hype by linking hereditary diseases

to particular genes, kicking off the field of gene therapy, and putting personalized genetic data into the hands of individuals. Yes, I'm talking about the modern DNA test kit. Think 23 and Me or Ancestry.com. I love these genetic tests, and I hate them at the same time. That's Augustine Fuentes, an anthropologist. just at Princeton University. We met up at the annual American Association for the Advancement of Science, or AAAS conference. Hello, how's it going? It is going well. And we talked about his love-hate relationship with these personalized genetic tests for our live show series.

This ability to take your spit and put in a tube, pay some 150 bucks, and have them send you something back about your DNA. That is amazing. But what it tells you, when they send you back your results, that splash page is never accurate. Because the thing it should say on that splash page is, congratulations, you are 99.9% identical to every other living human. That's not what it tells you. And aside from leaving out our similarities, most of these tests spit out results based on large geographic locations,

so continental ancestry. The problem is that these kinds of results think African, European, South Asian, are then linked to race, a social construct. Today on the show, we bring you the finale to our AAAS live show series. This episode, home genetic tests, what they can and can't tell you, and the misinformation about race and biology that comes into play when people, honestly eager and curious to learn about themselves, take them. I'm Regina Barber, and you're listening to Shortwave, the science podcast from NPR.

Okay, so right before the pandemic, I took one of these home genetic tests. My mom is from Taiwan and my dad's family is from Mexico. And I was super excited to see scientific evidence of all of this and maybe connected to these ancestral stories I've been told. So I started off the interview asking Augustine, who studies race and racism. I am excited to welcome Dr. Augustine Fuentes about these nuances of my results and about how my perception might have been off about what I thought I was getting from these tests. Just a little bit. Maybe just a little bit. Okay, so it says, like, legitimately it says 50% East Asian, roughly 30%, a little less, European,

almost 20% indigenous American and some like African and Arab small percentages. So these tests, they say that these are reference populations. So, like, what is a reference population? So, I mean, this is really the whole thing that you need to understand with these tests. What you just read, though, weren't reference populations. Those were continental categories, sort of an ethnic. or a group of people and then some country sort of areas. Yes.

So here's the deal. When you spit in a tube and send them, let's take 23 and me, your DNA, they analyze your DNA, this little teeny piece of it, right? They don't analyze all of it. And they file that in storage. It's like a compartmentalized cluster of information. These are reference populations. These reference populations, the data they have are how they place your DNA

and tell you something about it. Okay. So 23Me, for example, right now is about 46 of these. They used to have only like 37, but now there's more. Right. So they look at your DNA, and they look at all the reference populations they have, and they see which ones you're most likely to be similar to. Then they tell you, they don't say similarity,

they say you are X percentage of this group. Right. And that's not true. Your DNA is similar to that group. So if we were to take all 8 billion humans and divide them up into reference populations, do you think there would be more than 40 of them? Yes. Yes.

There are tens of thousands, if not hundreds of thousands of idealized reference populations in humans, so it sure as heck doesn't tell you where you are in the human panoply of genetics. So let's get into that. You're talking about these reference populations and tell us why it's not the same thing as continental ancestry because what you just said could still confuse people. Okay. So let's just define both of these things.

A reference population is a cluster of individuals who have their DNA sequence from some geographic place. Continants, big geographic space. So Africa, Asia, and Europe are not biological units, right? They're not even single geobiological patterns or areas or habitats or ecologies, right? They are geopolitical. We named them. We created these land masses and divided them in certain ways. So, for example, what is the difference between Asia and Europe?

Other than geographic location? When does Asia become Europe? Oh, I don't know. So there's a whole bunch around what we would call Central Asia today, depending on where you want to draw that line, or maybe even if you want to go all the way to the Balkans, you could draw the line there. It's been drawn many different ways because it's political.

So anyways, continent, big geographic space, reference populations, small group of humans from somewhere in geographic space. So with this distinction that you now have explained, what about these tests and what about how they present themselves and how they market? So the great benefit to these tests is they are actually telling you something about your DNA. The problem is that they don't actually tell you from the get-go how human you are, right? 99.9% identical to everyone else. It's 0.1% that varies across humans, 0.1% of our DNA.

They don't tell you sort of how that actually varies. They tell you you are X percentage, African, Asian, or European. because we think of continents, we think of Africa, Europe, and Asia as places that reflect biologies, that reflect deep lineages in humanity. And that's not true. So the danger in these tests is reifying that. You say, oh, I'm 17% African. Wow, I'm 17% black. Those two things are not the same, right? If you have 17% ancestry, let's say, from Africa on a test from 23 and me, and you're here in North America, most likely you have some genetic ancestry and population. populations from West Africa, right? That's interesting. That's fascinating. That's important. But that doesn't mean you have any relation to anyone in South Africa or East Africa or Central Africa or North Africa.

Africa is not a biological unit. There is no gene for race because race doesn't come from biology. It comes from racism. Right. And well, so you said like what they should say in that one sentence. It should say you're 99.9.9% human. At the beginning. But with the information they do give you, what more nuanced ways should they kind of? kind of represent this data. So let's get past that. You're all 99.9% just like everyone else on the planet. But look around.

You don't look the same, right? There are differences. There's huge biological variation. Humans are weird because we have enormous biological variation with very little genetic variation. So what can this genetic variation tell us? Actually, it is very interesting. You said you sent in your stuff.

It didn't tell you that much you didn't know. But what it did say is like, huh, why come I have this sort of what they're calling, you know, reference populations from Africa in me? Right. But what it can tell us is, where do you map related to these reference populations what does the movement of humans look like?

And the best thing they're doing now is you can ask sort of, well, where was I, where do my ancestors, genetic ancestors, where were they 200 years ago? Where were they 2,000 years ago? Where were they 10,000 years ago? And guess what? They're different places. Now, humans throughout history, right,

for at least the last 3 to 500,000 years, humans and our most recent ancestors have been moving around and having sex with each other regularly. Humans do that. And that's what we're from. But there is some stuff that genetic, tests do get right. So, I might be harshing on these ancestry tests, but they do tell you a little. They give you insights into some histories. They might validate or refute your own familial sort of

assessments. You know, there was that commercial where there's some guy who's sure he was German. When I first got on ancestry, I was really surprised that I wasn't finding all of these Germans in my tree. I decided to have my DNA tested through ancestry DNA. The big surprise was we're not German at all. 52% of my DNA comes from Scotland and Ireland. Neither of those two things German or Scottish are, in fact, genetic characteristics. But what it did tell that individual is that, look, your genetic history, your ancestry, some of the people that have contributed to who you are are coming from different parts of the planet over time.

That's fascinating. Yeah. And I mean, is there anything else useful about these tests other than kind of this? I mean, there's also some validation. We talked about, like, when you do have no history, right? when things were taken away from you because of racism, because of chattel slavery, like you're doing these tests so you can have some connection. Part of the story. I mean, that's really important.

History matters, right? Now, there's tons of types of ancestry, right? There's genetic ancestry, which is what we think we're getting from these tests. We're actually getting genetic similarity, but at least it gives you a hint of what your genetic ancestry looks like. But there's also genealogy, right? So I will tell you right now, my 23 and Me tests miss a bunch of my actual kin, right? Right? Because most of your ancestors contributed no genetics to you, right? Because of the way genetics mixes down and across. And here's the punchline for ancestry testing. It actually can tell you some information. When it comes to certain diseases, it's actually really important to know.

But it does not tell you who you are. And it actually doesn't tell you who your ancestors are. It tells you which peoples from different places contributed to your genetics. but that is not your family, right? Your genealogy is more than just the biology. Wow. Let's end on a high note. Okay. So the cool thing about these tests is that they're constantly updating their reference population.

So really cool part of this is that once you've done it, Ancestry.com, 23Mere, or any of the other companies, keep going back because as they expand their reference populations, lo and behold, your genes change. Everything changes about you. Basically, they just get more information so they know better about you. So, for example, I've been watching myself slide around like the Iberian Peninsula, North Africa, way over into Arabia, down into Sudan, back up, back over.

And then lately I've been shoved like way up into Russia. But what's interesting is that you learn more and more about all of the movement of those peoples that contributed to you and how we are all muts and how we are all muts and how we're, We're all this blend of amazingness of culture, of biology, of history. And so you can really enjoy reading these things, getting these reports, as long as you understand what they do and do not tell you. And at the end of the day, it's just sort of fun. I agree.

And thank you for talking to us. That was amazing. I'm going to shake your head like an adult. Thank you so much. Thank you for having me. Before we head out, I just want to take a minute to talk about Shortwave Plus. Plus subscribers help make our show possible, and they also get to listen to all of our episodes without any sponsor breaks. Find out more at plus.npr.org slash shortwave.

And to everyone who's already subscribed, we can't thank you enough. This episode was produced by Britt Hansen and Burley McCoy, edited by our managing producer Rebecca Ramirez, and fact-checked by Greta Pittenger. The audio engineer was Robert Rodriguez. Beth Donovan is our senior director of programming, and Anya Grenman is our senior vice president of programming. I'm Regina Barber. Thanks for listening to Shortwave from NPR.