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Comment by crazygringo | Hacker News Reader

Does a claim like this even have any meaning at all?

If you assume each generation is 25 years, then everybody alive today has 2^200 ancestors from 5,000 years ago. Which is obviously way more people than even existed in the world because your ancestors start overlapping, but the point is that you could probably make the claim that "half the human beings alive today" are descended from tons of groups of humans that existed 5,000 years ago. People travel and migrate and marry and genes get passed on at an exponential rate.

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I'm glad someone gets the intuition of the Charlemagne paradox. In fact ALL people today are related if you go back 3000 years, but the aboriginees might have very little DNA from the pharaohs. The point is that ONE individual 1500 years ago traveling to Australia (and bringing the dingo) is enough to connect these graphs. The only question is: how related. 0.0000001%? ;)

Actually it's even more complicated. every human has 50% DNA from each of parents. And at the same time 60% DNA common with banana.

Wouldn't that assume each parent had totally different DNA? Seems like there would be more than 50% DNA from each parent. At the very least there would be an enormous amount of DNA that just qualifies us as human, in general.

It means that if you trace Y-chromosomes back 5000 years, you'll find that grand-grand-grand-...-fathers of 40% of people are concentrated in the area of the Yamnaya culture. Grand-grand-grand-...-mothers would be from multiple groups, yes.

I don't think they are claiming 40% of males today have y-haplogroups descended from the Yamnaya

r1b's population is only 190 million [1]

[1]https://www.razibkhan.com/p/the-haplogroup-is-dead-long-live...

The article reads "some four billion human beings alive today—can trace their ancestry to the Yamnaya". It's 50%. I haven't checked the research though.

> r1b's population is only 190 million [1]

Their population likely had multiple haplogroups. R1b was the most common (5000 years ago). But, yeah, the 50% number looks too high.

> you could probably make the claim that "half the human beings alive today" are descended from tons of groups of humans that existed 5,000 years ago

Surely it's still notable to identify specific groups for which this is true, particularly when the group itself is primarily identified by an unrelated archaeological characteristic.

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