Do genetic ancestry tests know if youre Palestinian? A cautionary tale of race and science

Science Friction


Welcome welcome to size friction on the tension ritual in. Today's episode is Genomic Science to go to striking story for you of the shocks. You can engage when you take a genetic ancestry tests and the problems are not in your Diana. They are in the science. Oh man so so I want you to make mercury eight to buy. Oh my gosh. So she's an American Palestinian cartoonist illustrator. Leaving in Brooklyn New York and when Shae Shea started to draw well I kind of helped his stop making sense of the world. When I was younger all I wanted to do withdraw from Warwick fantasy characters? who were you know exploring some fantasy world adventuring trying to figure out the meaning of war? Yeah you Matz I. She was an intense keyed. He'd sigh relate to that. I'm not even joking. That was my first comic when I was like thirteen or fourteen trying to figure out the meaning of war yes the law plot. What was really hard? Core rate was trying to figure out the world her family stories. We're helping figure out a self my family. So my my Palestinian side of the family were originally from Ramallah they came to the US in the sixties after the nineteen sixty seven war. And and. That's where my father. My mother my mother is mostly of British and Scottish ancestry and they met in DC and the register and Marguerite was born. She grew up in San Francisco but she understood whole lot about the deep heritage in history. If if family I lived with a lot of my extended family on my father's side and and the constantly I mean I think it's a very Palestinian thing to talk about loss. I'm sorry to say Palestine and talk about what was lost in talk about how it was and things like that so I heard very much about out where we were from and how it was there and everything and there is actually a book. That is a congenial logical history of Ramallah so my family needs to say his in this book. This is actually a book that was done maybe thirty years ago. There's actually a recent effort to update the books so this is kind of a big thing and it's very much a Palestinian thing to try to keep memory alive. It's a need to assure after that. Hey you know we exist who've had the we had this entire history. We're going to write it somewhere. We're going to you know. Put it somewhere. I wish I could've seen Palestine back in the day honestly because it just sounds really chill a nice. I'd like to go okay. Okay so mercury thought. She had a pretty clear idea about her ancestry but then she sped into a test tube. Well first half-brother on her father's side spat into a test tube. He decided on a whim to take a day and I taste and he got the results back in he was just blake. Yeah you might want to take a look at these results. He's her kind of weird. Well we'd in an intriguing conaway. Our understanding ending was that from my Dad's side. We were fully half Palestinian half Arab but these results they suggested something different so so we were just like what so marguerite decided to do an ancestry test to this was back in two thousand sixteen. They went through twenty three and me did the all spit in a tube and she said it off to the company twenty-three May and literally Chino. Even more surprises would be in store for her so the saliva gets to our partner lab. The DNA is extracted from that. and My name Ms Joanna Mountain and I'm senior. Director of research at twenty three and me and previously at Stanford with Joanna also did her PhD and specialized in human evolutionary evolutionary genetics. So when customers sign on with the genetic testing and Analysis Company twenty-three May which is headquartered in Silicon Valley. He's what what happens to this speech sample around a half. A million positions in the DNA are analyzed and we get the genetic variants at those half million positions genetic knitting variant. Now that just means some kind of unique variation in your genomes deny say quance so then twenty three and me use an automated computerized Haraz prices to p different stretches or windows of your day and I and then I compare those two James off a reference group made up of individuals individuals from different populations globally. Now what ethnicities are present or missing from that reference group. That's K. as you'll he'll IDA and and we look at each one of these little windows and we say to which people is this individual most genetically similar and we continue as we stroll along the genome looking and saying well at this point this genome looks very similar to people from say Iberia and then we get a little further down in. Wow it looks similar to people from commoner and even in further down. It looks similar to people from Ireland. So there's a method we have that classifies each little patch of the genome by saying. Is this more similar to people from Ireland Orland or from France and then the algorithm says okay the probability that's from Ireland and appropriately. France in whichever is highest. Is the winner there so then we patch it all together come up with percentages for each individual so it's a multi step process and that's what we present to the customer okay so back back to margarite radium waiting for the results from twenty three and May to land in her inbox and sure enough. I got I got the results back and Some of them made sense. You know I knew enough about my mother's side of the family told me that okay. HALF OF ME is British and Scottish Scottish. Okay cool makes sense what came next made very little sense to her. Other half is going on percent Italian Elian it said thirty five percent Italian and then the rest was Arab Specifically Oh what did it say. Think specifically had said western Western Asian or something they actually tried to give me a breakdown of what regions of Italy it came from but they couldn't actually detect wherein Italy. It came from at all Wade. It'll Italian come from and actually I think is sweet coincidence. Is it true that your husband is Italian. My husband is Italian and I did actually when I got the test I did ask him like do I look talion. He was just like no suddenly just like that. Migrate was possibly thirty percent Italian and only fifteen percent western Asian and north African and canete slightly saving detail that she is Palestinian heritage. We'll wait until you hear what happened. Win Twenty Twenty three and may updated her results two years later. It's fairly incredible. I though Hel genetically different we really well at the genome scale there. Her over three billion nucleotides that make up our genome. So My name is Sarah Tishkov and I may professor of genetics awesome biology at the University of Pennsylvania and she's hugely influential Sarah and colleagues published the first pipe to support the out of Africa hypothesis of human migration using analysis of the DNA inside cells Nuclei and has conducted the largest studies of genetic variation in in African populations. We differ at about. I would say less than point. One percent of the genome. So that's a relatively small mall amount of difference to give you an idea of we. Compared the human genome to a chimp genome. It differs at about one point. Five percent of the genome less than point point one percent and yet what is contained within that variation that difference the majority of variation is not functional and in fact that variation is very useful for making inferences about evolutionary history about population history demographic McGrath history tracing migration events and so on the part of the genome it actually is influencing variable traits is important for understanding how how we adapted to different environments during human evolution and also understanding why some people are more at risk for certain diseases than others

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