Best of: Your 23andMe Really Doesn't Show You Much
It only takes one generation to change the answer to “where do you come from?”
There’s been a lot of intensity in the news cycle lately, and I’ve been spending a lot of time talking about modern problems lately — social media, AI, smartphones, governmental regulations, etc etc — so I wanted to take a moment to reflect on our deeper, more ancient experiences. Our species has been around for a long time, and I find that taking time to look back into our ancient, shared pasts can do a lot to reframe modern conversations.
Back in the early days of this substack, it had been recently discovered that the famous “iceman” found in central European mountains had been born in Anatolia, or what is now Turkey, and he had naturally darker skin. It was one of those revelations that, paired with several other findings and studies on prehistorical Europeans, really hammered home just how recent so much of what we understand to be integral to identity really is. Put another way: 99.9% genetic similarity means a hell of a lot more than the superficial characteristics we fixate on, and the notion of a nation, let alone an ethnicity, is so much more watery and fragile than we usually insist.
One last thing: I really wanted to plug the movie Alpha when I had originally written the following article, but I neglected to. So I’ll do it now: watch this movie. It’s set in Europe 20,000 years ago and depicts a hypothetical story for the domestication of the world’s first dog. (No, the dog doesn’t die. I have to answer that question so much I’m just going to cut through the butter up front. It’s a happy movie).
Alpha is incredibly well done, and thoroughly researched. One of my favorite aspects of it is the reconstructed language, created by anthropology professor Christine Schreyer, who was inspired by Proto-Nostratic, Proto-Eurasiatic, and Proto-Dené–Caucasian. Kodi Smit-McPhee just runs away with this film — it’s an amazing performance.
Possible double feature: follow it up with 1981’s Quest for Fire, which stars Ron Perlman and Everett McGill (from Twin Peaks). This one depicts crossovers between Homo sapiens and Neanderthals and is set even farther back in our shared human past.
Recent genetic analysis found that Ötzi the iceman, a hunter-gatherer that died in the alps along the modern border of Austria and Italy about 5,000 years ago, is actually about 92% Anatolian and had much darker skin than is typically depicted.
“I would say that you only have to look at the mummy. It likely represents Ötzi’s skin tone pretty well….It used to be thought that Ötzi’s skin got darker when he was mummified in the glacier, but actually this theory could not ever really be explained. Now we know that the Iceman’s skin color was in fact as we see it now.
European ancestry is more dynamic than we usually give it credit. Only 5 years ago the news cycle got hit with a new construction of Cheddar man, showing that Britons only 10,000 years ago had dark skin and blue eyes.
“This is a very unusual phenotype, quite different from the way we have until now imagined the original Europeans,” says Dr. Johannes Krause, the archeogeneticist behind the recent Ötzi discovery.
By the late Bronze Age, people in Europe were getting lighter very quickly. In fact, there is hardly a gene that has spread as fast as the genes for light skin color in Europe. We suspect this has to do with vitamin D and the change from hunting and gathering to farming. Early farmers took in very little vitamin D with their diet. However, humans can also produce the vitamin in their skin because of a precursor which reacts to penetrating UV light. Low pigmentation allows more UV light to penetrate. So, there was an advantage for light skin to survive in a Europe which was quite dark with little sunlight in winter, especially if you were a farmer.
A 2020 study found that the genes for lighter skin spread as late as 5,000 years ago, directly corresponding with the advent and spread of agriculture, which developed in ancient Anatolia about 8,500 years ago, spreading to most of continental Europe over the next thousand years and reaching modern Ireland and UK only about 6,000 years ago. Imagine what this two thousand year window brought: populations tanked from malnutrition and their skin abruptly whitened in just a dozen generations.
So why then did Ötzi still have dark skin, if there were tribes in the area of his death that had been practicing agriculture for centuries?
With Ötzi, this development had not yet been reflected, perhaps because he lived in southern Europe or because within his population there was still enough vitamin D from the diet at the time, through fish and meat for example.
None of his European contemporaries whose genomes we have available, and there are hundreds of them, share as much ancestry with early Anatolian farmers as Ötzi. It suggests that he came from a relatively isolated population that had little contact with other European groups, and that not so many hunter-gatherers lived in this region.
Anatolia is about 1,500 miles (~2,400 km) away from the Alps, and a journey of that length could be taken on foot in about a month. For nomadic hunter-gatherers, this is not that big an ask.
This is precisely why these consumer-facing companies making sweeping claims about ancestry really cannot be taken too seriously at face value (among many other reasons, such as identical twins receiving significantly different results).
What does it mean to have, say, French ancestry? For one, the Franks (a German people!) did not conquer the territory we now call France until the 5th century CE. Before that, it was Roman-dominated Gaul, meaning that the people there were mostly Celtic and Mediterranean. As for the Celts, “they” had only “been there” for the preceeding thousand years, with their culture spreading into that area between 750-450 BC, reaching the time of the Mayan civilization, the Roman Republic, Confucius, the Buddha, Socrates, and even Heroditus, who is considered the “father of history.”
Before the bronze age we have the neolithic period, covering 5,000-2,000 BC, the mesolithic before that going back to 14,000 years ago (the time of the Younger Dryas, or the last years of the Ice Age.)
Following that, the upper paleolithic period (formerly called Cro-Magnon) stretches back about 30,000 years, which is when Homo sapiens and Neanderthals interacted and comingled. Think about how much migration and change can happen in 30,000 years. Now think about this in the context of anatomically modern Homo sapiens being at least 200,000 years old.
This is why when you break down Ancestry and 23andMe results, you get answers like “broadly European” and “broadly African” and so on and so on. These results are almost meaningless when you try to imagine what “European” even means over the stretch of a fifth of a million years.
So, knowing what we know now about white skin and blue eyes only stretching back 10,000 years at the most, you don’t have to go that far back in time before you start picturing prehistoric Europe as looking a lot more like this:
Now I’m not saying you should be saying something as simple as “ancient Europeans were African.” No, they lived in what we now call Europe; whatever they looked like they were European. They certainly had ancestry stretching back to Africa, but it only takes one generation to change the answer to “where do you come from?”
That’s exactly my point: a geography certainly impacts phenotype over generations, but considering that we are such a dramatically migratory and nomadic species with a rich and fluid history, it’s foolish to try to tie who you are now to an ancestry that is as amorphous as an ocean.
“After all, it is precisely studies such as these that show that our ancestors all immigrated at one time or another, that we are all a big genetic mixture.”