Many people from Peru and Bolivia (edit: I guess also Mexico) also inherited some genes like these in Tibet that let you breathe at high altitudes. I'm wondering if it could be the same explanation since natives of the Americas allegedly crossed that land bridge from Asia. These people's chests and lungs are quite large compared to a normal person and you can see it in the body type.
This could also be explained by convergent evolution [1] where a similar trait was created by an independent evolutionary path.
The wiki page for 'High-altitude adaptation' in humans even mentions that adaptation to high altitude arose independently among different highlanders as a result of convergent evolution. [2]
Interesting that you said that. I've concluded long ago that the only way we can successfully live off earth is to adapt our bodies to live with different gravity, air pressures, etc.
Be it space or submarine habitats, at some point it has to make sense to have some workers who are adapted to hypoxic situations, if only for emergency work. You go to work, you have kids, the kids fall in love, you have grandkids that might have one, both, or neither of the genes. A few more mingled generations and a little selective pressure here and there and soon you have specialists with two copies of the genes.
I think it's plausible for things to play out something like this, a bit different from Kim Stanley Robinson's predictions in a few critical ways:
You have a group of people on Mars who can survive and reproduce in cheaper habitats than everyone else, eventually they'd realize they could sod off and do their own thing. Lower barrier to entry maybe overcomes economic and political pressure, and pretty soon they outnumber everybody else. Your first group that refer to themselves as ethnic 'Martians': Tall, dark skinned, barrel chested (because of the air) individuals who speak a pidgin of English, Amharic, Quechua, and a handful of Tibetan words, and don't answer to Earth.
They are the first people who can walk the terraformed surface without equipment, and they explode out onto the surface. A fresh wave of earthlings from above 10,000 feet arrive and bolster the numbers and gene pool. As terraforming continues, a second wave inundates the First Peoples with many immigrants who swarm to the lowlands. There is a comedian who does an entire monologue on the crazy customs of the New Coloradans, and how they never seem to get along with the New New Mexicans (which leads to 3 full minutes of material on why the hell they called it New New Mexico). For her second tour, she asks why so many Mormons are there. This trickle never really slows down, and Albuquerque and El Paso become a kind of continuous concierge service where people come to live for a year, and then either go home or to the space port to fly to Mars (people who go through Albuquerque have better outcomes, but El Paso competes on price).
Eventually a third wave brings people from everywhere, and the 'Old Ways' find themselves in the highlands at first, and on the slopes of Olympus Mons later, where no amount of terraforming will ever create a popular destination for lowlanders or Earthers.
The genes have already evolved, you're just selecting for them, which doesn't take long.
The rich have access to gene editing. I seriously doubt working class Martians will. And I'm not sure that safe gene editing will get here before Mars colonies do. I could see it going either way. People will try it anyway, and some will win the lottery while others lose.
We already have gene editing. Last week's "60 Minutes" featured a young woman being cured (so far as the doctors can tell) of sickle cell anemia with gene editing.
