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Comment by novalis78 | Hacker News Reader

So how did this evolve over the past 1000 years? Selection pressure? The ancestor who could dive better had more children? Could feed his family better? Was it just one person with mutation that started it? Or, did the frequent exposure to deep diving triggered something in one generation that influenced the genes of their children (along the lines of Epigenetic magic)?

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    > So how did this evolve over the past 1000 years?

The article says "For more than 1,000 years". That doesn't mean that whatever features these people have have evolved in that time period, but that they ran into the limits of recorded history. Humans have been in that area for around 50,000 years.

It's entirely possible that the current tribe derives from some subset of the population that's been doing this sort of thing for much longer than a millennium.

    > Selection pressure?

Maybe, but one thing you and the other replies haven't touched upon is the possibility of selection bias.

These people aren't in isolated population on some island in the middle of nowhere. They've been living around other humans for their entire existence.

So it's possible that this population today isn't just the result of selection pressure, but selection bias. People who were good at hunting underwater due to their genetic aptitude would have found and joined the tribe, who were happy to let them in as they were good at underwater hunting and could pull their weight. Conversely, those in the tribe who weren't good at it might have left the tribe entirely.

The article didn't mention culture, but I would venture to guess that in a society based on diving, the most skilled divers would be the most sought after mates.

This ability gives you a huge competitive advantage in times of limited resources, so most likely others have died/had limited offspring.

Even something more modest like "had on average 0.01 surviving offspring" could make a big difference over many generations.

See the top comment and see how this DID not happen. In any case, if it DID happen this would not have been "evolution" it would have been adaption; in other words selection for genes that are already there. It would not have been the result of new genes.

Evolution mostly works by selecting on variants in existing genes. The large majority of de novo mutations are either neutral or negative. If traits are selected for or against in the population and change in frequency that absolutely is evolution. Andean Indians have different adaptations to Tibetans to living at high altitude in part because the genes involved have been under selection for different lengths of time. Andeans have poorer adaptations because they have been living at those altitudes for a shorter time than Tibetans. The Tibetan adaptations introgressed from archaic hominids, not H. Sapiens, but the Andeans didn’t have that advantage. The term to google if you want to learn more is selective sweep.

There are many examples of recent selective sweeps in recent human evolution, from lactase persistence in Indo-Europeans to depigmentation in people who live at high latitudes.

>>The ancestor who could dive better had more children? Could feed his family better?

I think so too. Also the deep diver got the most beautiful /youngest /healthiest bride who would in turn bear healthier children. Rinse, repeat, with the offspring who inherited same genes. Over 1000 years of the same, the population changes.

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