Is the Future of Medicine Hidden in Ancient DNA?

from The New York Times I'm Sabrina. tavernes and this is the. [Music]. daily in a major new advance in science. DNA from Bronze Age skeletons is. providing new Clues to modern-day. medical. Mysteries today my colleague Carl Zimmer. explains how a new field of science is. changing the way we think about treat.

ments for devastating. diseases it's Wednesday January. [Music]. 31st so Carl you are a science reporter. as our listeners will know and you write. about Evolution and the origins of life. and you've recently written a story that. really piqu my interest it was about a. major new discovery in our understanding. of ancient people and it's leading to.

some big advances as I understand it in. modern medicine so tell me about it well. scientists have been wondering about two. big questions for a long time one of. them is why do we get sick the other. question is where do we come from and. they seem like they should have two very. different answers but now scientists are. starting to realize maybe the two. questions actually have the same. answer the me answer how Carl well it's.

possible that in order to treat the. diseases we have to deal with today. diseases often that have no treatment. yet it may be necessary to go back. thousands of years and look at how our. ancestors lived then what were the. challenges they faced what was their. health like what kind of genes did they. carry and maybe we can then come back to. the present and start to be able to make. make our own health better and now.

researchers have just made some really. big discoveries both about human history. and about our diseases at the same time. and this history actually lives inside. of us right now in our own genes and has. big implications for our health okay so. two branches of science coming together. as you say making some major new. discovery so tell me about this first. field of science Carl what's happening. there well you know once upon a time if.

you wanted to study ancient life you. were pretty much limited to. fossils you know after an animal or. person died their body is decomposed and. if you're lucky their bones managed to. survive in. rock and then thousands or millions of. years later a paleontologist would come. along and dig those fossils out but. now it is actually possible to to dig up.

those bones and to drill a little sample. out of them and find some DNA still. surviving in. it so this actually gives you a glimpse. into you know the. molecular life of these ancient people. or ancient animals and it's amazing. enough when scientists can get just a. single Gene out of a fossil that's.

thousands and thousands of years old but. actually the science has come so far in. recent years that it's pretty common for. scientists to get a whole genome of an. extinct species that is like every. single Gene every stretch of DNA uh. reconstructed pretty. [Music]. accurately once you can look at the. whole genome of some ancient organism.

you are really starting to get the big. picture of how that thing lived and. looking back at our own past we can. actually use this ancient DNA from. fossils to figure out some clues about. our ancient relatives going back a. couple hundred thousand years actually. and this includes ancient relatives like. neander tals for example so now we can. actually see an entire Genome of neander. but more recently what's been really.

spectacular is actually how scientists. have been able to focus on the past. 10,000 years and what we're talking. about there is that time in history. where hunter gatherers started to. domesticate animals and plants and start. to farm when you started to have the. first towns when you started to have. first large scale societies and we can. actually go now and see what the DNA of. these people look like actually we can.

see thousands of people from this time. period okay so we're really getting a. clearer picture of how groups of ancient. peoples came to be and live their lives. many many years ago but how specific is. that picture like what does it look like. what are some of the things we're. learning. Carl we're learning about all sorts of. things about these people's lives by. looking at their DNA I mean some people. today you know they can drink milk and.

be fine with that and some people are. lactose intolerant well we can actually. look back at the DNA and say who was. lactose intolerant uh among ancient. Farmers 8,000 years ago we can say that. we can start to actually get clues about. the color of the skin of people who. lived 10,000 years ago we can figure out. how societies were organized when you. come across a burial with several. skeletons in it when they all have. jewelry on it you can actually show. genetically if if they're related or not.

and that might tell you you're looking. at say a royal family and on top of that. look at how these different groups of. people with certain genetic markers. moved around how they expanded from one. place to another how two populations. might interbreed so there's an. astonishing amount that you can learn. now from ancient DNA so we're basically. seeing the stories of different groups. of people over time yeah that's right. and there are group groups of people.

that we didn't really know much about. before people who existed thousands of. years ago who now were realizing were. actually really important to the course. of history and one of those was actually. a group called The yamnaya okay yamnaya. that is not a group I am familiar with. not a household name well archaeologists. have known about the. Yuma to some extent for for decades but. they couldn't really say that much about. them what has become clear now is that.

the Yuma were living you know maybe. 6,000 5,000 years. ago they started out as Farmers but they. actually gave up farming because they. developed this practice of hurting. cattle and sheep and goats and they were. incredibly successful at this and they. were among the first horse. riders they would use the horses and. other livestock to call wagons and they.

would just go across hundreds of. thousands of miles of the step from the. Ukraine all the way over to Central Asia. to places like. Kazakhstan they went from roaming around. to exploding across Europe and. Asia and when they showed up they took. over and you can see this actually when. they arrive in Denmark for example. scientists have looked very closely at.

the DNA in Denmark from skeletons over. the past 10,000 years and you can see. that there's a group of farmers there. with a certain kind of ancestry and then. boom the yamnaya show up about 5,000. years ago that's it it's all Yuma so. they showed up in northern Europe from. Central Asia and at some point became. the dominant population that's right we. don't know exactly how that happened. there are some very dark possibil ities.

this could have been some kind of. genocide or maybe it wasn't such a. violent transition maybe it was a. competition for land that took decades. to play out but in any case we know that. the. yumnah became the people of the region. and then they became the ancestors of. people in northern Europe today people. today with northern European. ancestry they come from the ynah and. Carl why are these people important I.

mean why are we talking about yamnah in. the context of this genetic stuff well. in addition to being really important to. the course of history um they actually. matter to us. today because locked inside of their DNA. 5,000 years ago are some really crucial. secrets about some of the most. devastating diseases we suffer from. [Music]. today.

we'll be right. [Music]. back so Carl you said that this new. science was showing us something. important about these yamnah people and. it had to do with disease this little. code locked inside their DNA tell me.

about that so this brings us to the. second field of science I was talking. about which is the basic question of why. we get sick we get these diseases and. they seem to have all sorts of just. random. symptoms but if you can understand their. history if you can understand their. evolution maybe they're not as random as. they seem Maybe by understanding their. history we're going to be able to treat. them. okay so this is these two fields of.

science coming together like a kind of. you know scientific chocolate peanut. butter Reese's Peanut Butter Cup but. what's the process once they come. together like how do you study disease. in ancient people so on the one hand you. have some scientists who are looking at. the DNA of living. people and. finding different variations in their. genes that put them at risk for certain. diseases.

there are genes that can raise your risk. for heart disease for cancer for. schizophrenia for all sorts of. conditions and scientists have actually. been able to create pretty long lists of. these genes where there's strong. evidence that if you have a certain. version of a gene you are at a greater. risk of getting these. diseases and so these scientists who are. pulling ancient DNA out of bones that. are 5,000 10,000 years old are saying. well let's see if these people who lived.

thousands of years ago had those genes. too when did these mutations arise and. how did they spread let's trace the. whole history of these mutations that. today put us at risk of different. diseases so how exactly do they do that. well one of these projects is based on a. British database called the UK. biobank.

what happens there is that half a. million volunteers have submitted their. DNA and allowed scientists to compare. their DNA to their own medical records. and so that they can see links between. their genetic variations and the kinds. of diseases they're suffering from so. basically these scientists are tracing. the diseases people have to mutations in. their genes and looking for patterns of. cross populations that's right and so.

then what you can do is you can compare. their DNA of these living people in. Britain to all of this ancient DNA from. across Europe and Asia and you can try. to figure out well where is their DNA. coming from who did they inherit their. DNA from and did they actually inherit. some of these disease genes from those. ancient. people. so it's kind of like a 23 and me to.

figure out who you were related to in. the Bronze Age right and whether they. passed down anything to you that might. make you sick now that's right and what. they found were mutations that today we. know increase people's risks for a whole. bunch of different diseases but with a. Twist some of these mutations were. beneficial to those people thousands of. years. ago okay that is kind of mind-blowing.

okay so explain that to me Carl what's. an example so we can go back to the Yuma. for a really powerful example of this so. the Yuma were hurting. animals they were with their animals all. the time they were just going back and. forth along the step always with the. animals and that was great because that. gave them a source of meat it gave them. a source of milk of leather wool like.

this incredible resource that you have. right on hand but animals have something. else they have. diseases and so if you're going to be. living with animals you are actually at. risk of picking up some of the diseases. that they're carrying so Carl were the. yumnaa the first people to actually live. with animals and then therefore get sick. from them well the Amah were getting. diseases from animals at a rate that was.

really different than people had before. because they were living with these. animals so much of the time and we. actually know that because we can see it. for ourselves in their bones when you. drill into the bones of the yamnah or. other ancient people you can get out the. DNA of the people themselves and. sometimes you can also get the DNA out. of the germs that killed them H amazing. it is amazing and we know for a fact.

that they were dealing with a lot of. diseases and it turns out that they were. actually evolving a resistance to. them evolving resistance to them how. exactly so if you had a mutation that. ramped up your immune system so that you. were better able to fight off these. germs that were spilling over from these. animals all around you that would mean. you're more likely to live long enough. to have kids and pass down that Gene to.

them so if you look across the DNA of. Yuma they have a lot of. mutations for the first time that are. associated with a really strong immune. response but there's something else. that's really important about these. genes in the. Yuma these are some of the same genes. that. today can put people at risk for certain. diseases one of one of those diseases is. multiple.

sclerosis multiple sclerosis like very. debilitating disease that's right yes. when people develop multiple. sclerosis their immune cells look at. their own nerves as the enemy they. actually will attack the nerves in the. body and this is incredibly debilitating. um it can progress to the point where. people can't walk have trouble talking. you know it affects millions of people. today and yet we're seeing some of the.

genes that put people at risk of Ms. today actually being. beneficial in the yumnaa okay so explain. that Carl like how was it protective to. the Yuma but obviously very debilitating. and problematic today like how did that. happen so if we go back to the yumnah. four or 5,000 years ago they are being. exposed to a lot of diseases a lot of. bacteria maybe a lot of viruses now. recently like in the past Century a lot.

of those pathogens have gone away so you. have pasteurized milk you have clean. water you have all these innovations. that make these pathogens much less of a. threat to People's Health but they still. have this aggressive immune system they. still have an immune system that evolved. for this tug of war with the pathogens. and now if the immune system is not. being continually challenged by these.

pathogens it looks like sometimes the. immune system makes mistakes in it's. aggressiveness it. misfires so that there are opportunities. to get confused and to start to look at. a person's own body as the enemy okay. that's pretty interesting that like. something that was so protective Through. the Ages suddenly becomes a real. hindrance because everything changed. really in the past 100 years or so but.

how exactly does knowing this actually. help people who have MS today Carl what. are the practical implications here well. it helps us to understand why it is that. some people get Ms and other people. don't Recent research has pointed to a. virus called Epstein bar as the trigger. for Ms and other words you probably. don't get Ms unless you get infected. with Epstein bar MH but the fact is that. most people get infected with mcen.

bar and maybe a couple million people. have MS so clearly there's something. special about these people and what's. special is that they have inherited. these genes and if you can. understand how those genes first evolved. what their functions were for 5,000. years ago that can actually help you to. understand how they're going wrong now. so you know right now there are some you. know fairly effective treatments for MS.

they're okay for some people they're not. great for others but they're crude. they're kind of like a sledgehammer. basically they just sort of take the. immune system and just dial it all. down that's good in some ways because. then your immune system is not going to. be attacking yourself so readily but you. know like you do need your immune system. actually do need it to avoid getting. really sick from. infections so really what we need need. to do is find a better balance we need.

to understand that what's happening is. that the immune system just has lost. this partner in this dance of survival. and so how can we mimic that are there. drugs that could actually like give the. immune system that balance again without. us having to get really sick and things. like that okay so understanding the. origins means we go from treating Ms. with this big Sledgehammer to a little. scalpel right we can really fine-tune.

the treatment that's right and we start. to understand you know. why different people are at greater risk. of getting Ms you know why are the rates. highest in northern Europe you know. people came up with all sorts of stories. for a long time but we actually know why. we know because the Yuma showed up so it. takes some of the randomness out of it. right this research has helped us. understand something incredibly.

important about this very debilitating. disease it has and this is really just a. trial run for this whole approach this. research was based just on the UK biopan. just on people in Britain but when we. look forward it's not just going to be. British people whose history scientists. are going to be unpacking it's going to. be people all over the. [Music]. world we're going to be learning not. just about multiple sclerosis but we're.

going to be learning about diseases like. heart disease diabetes uh conditions. like. schizophrenia and it may be possible to. understand how it is that actually maybe. the genes that put us at risk of these. diseases today or giving us other. benefits thousands of years. ago so in effect we could be sitting on. a whole new cache of future cures right. in all of our archaeological sites like. is the future of medical research.

paleontology it could be it could be. this is what scientists sometimes call. evolutionary medicine but really up till. now it's been more of an idea than a. reality but the experts I talk to say. that with ancient DNA research like this. evolutionary medicine is now finally. coming of. age Carl thank you thanks so. much.

[Music]. we'll be right. [Music]. back.

here's what else you should know today. on Tuesday in a partisan indictment of. President Biden's border policy House. Republicans began pushing through. articles of impeachment against Homeland. Security secretary Alejandro mayorcas. Republicans are poised to charge. mayorcas with refusing to uphold the law. and with breaching the public trust in. his handling of a surge of migrants. across the US border with Mexico. Democrats and many legal Scholars say. the committee has not produced any. evidence that the secretary has.

committed an impeachable offense even if. the house votes to impeach mayorcas he. is not likely to be convicted or removed. by the Democratic controlled Senate but. the action could force an election-year. trial on the politically charged issue. of immigration and the southern. border and Hamas said it was considering. a proposal to pause the fighting in Gaza. and exchange Israeli hostages for. palestin. Prisoners the deal's terms were.

finalized in Paris over the weekend by. the United States cutter Egypt and. Israel and involves a 6-week ceasefire. in exchange for the release of more. hostages in a statement hamas's. political Chief Ismael hania suggested. that the group was open to the deal but. also reiterated its long-standing demand. for a total withdrawal of Israeli forces. from Gaza one that Israel has repeatedly. rejected.

today's episode was produced by Alex. Stern and Jessica Chung with help from. Shannon Lynn and Carlos prido it was. edited by MJ Davis Lynn with help from. Mark George contains original music by. Chelsea Daniel and Dan Powell and was. engineered by Alyssa Moxley our theme. music is by Jim brunberg and Ben. lansberg of. wonderly that's it for the Daily I'm. Sabrina Tavern see you.

[Music]. tomorrow.