Hello everyone, welcome to the Mindscape Podcast. I'm your host Sean Carroll. We talked about DNA

and genomes here on the podcast quite a bit. There's a lot of information locked up in our DNA,

both information about how we as organisms or other organisms function right in the here and now,

but also this information about our history. Remember a few months ago we talked with

Betul Kachar about paleo genomics, learning about very, very early life by looking at the current

genomes of different organisms and seeing what they have in common. But if you want to look at

human history, you're talking about thousands or hundreds of thousands of years ago,

not billions of years ago, and that gives you a different thing that you can do. You can

look at the actual DNA of the actual humans from tens of thousands or hundreds of thousands

of years ago. Can't do that if you're looking a billion years ago, there's no DNA left from a

billion years ago. So this is a new field of science that has really exploded in the past decade or

two, learning about ancient human history by looking at the actual genomes from skeletons and

fossils of real human beings who lived back then. And today's guest David Reich is one of the world's

leaders in this field. He's made many discoveries along these lines in his lab. Perhaps most

provocatively, he's one of the people who discovered the fact that there is Neanderthal DNA in most

human beings today, other than Africans, other than people whose ancestors have been in Africa the

whole time, most other human beings have a tiny amount of Neanderthal DNA mixed in. So this tells

you something since Neanderthals were Europeans and Asians predominantly, and human beings,

homo sapiens came out of Africa, what this means is that when the humans came out of Africa,

they got it on with some Neanderthals, right? They mixed up the gene pools a little bit,

and that kind of analysis can be done at many layers in many different times, and we learn a lot,

a lot of surprising discoveries have been made. I don't want to give away all the surprising

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