Untangling Ancient DNA

Friday, April 18, 2025

Untangling Ancient DNA

There’s been an amazing amount of progress in reading the ancient genetic code—the DNA—of human ancestry going back many thousands of years. That was the subject of this podcast discussion with geneticist David Reich, here from Spotify:

I had not previously heard of the podcast, but the YouTube algorithm reckoned it might appeal to me. The YouTube version of it is here:

Here is the episode’s YouTube description:

I had no idea how wild human history was before chatting with the geneticist of ancient DNA David Reich.

Human history has been again and again a story of one group figuring ‘something’ out, and then basically wiping everyone else out.

From the tribe of 1k-10k modern humans who killed off all the other human species 70,000 years ago, to the Yamnaya steppe nomads 5,000 who killed off 90+% of (then) Europeans and also destroyed the Indus Valley Civilization.

So much of what we thought we knew about human history is turning out to be wrong, from the ‘Out of Africa’ theory to the evolution of language, and this is all thanks to the research from David Reich’s lab.

The subject matter grabbed me particularly because the segments about the Yamnaya influence on our European lineages fill in some details behind the preexisting idea of a Proto-Indoeuropean language: a hypothetical parent language for everything from Greek and Latin to Gaelic, Hittite, Iranian, and Hindi. There has been very little doubt that these languages are related because they share so much related vocabulary—much more than you might expect for loan words to a language’s core vocabulary.

Core vocabulary encompasses the words that we acquire as children from the earliest phases of language learning at home: They are the most conservative parts of the language in terms of change. They are frequently irregular, preserving historical features of a language’s discarded grammar. Philologists have found many similar features of languages that are geographically very far apart in the case of Indo-European languages.

This was the first I had ever heard of the podcaster, Dwarkesh Patel. The couple of episodes that I’ve taken in have the qualities that interest me in podcasts: It’s subject matter that I find novel, and the host does the reading before the interview. The discussions are thus focused and informed, and not just windy rambles like some college dorm bull session.