Let us suppose that Elon Musk makes substantial progress in Mars colonization. There’s a problem* – it’s not clear that current Earth humans could thrive there. The gravity is a lot lower: we know that zero G is bad for you, and 0.376 of Earth standard might not be survivable, over a lifetime.
But that’s no reason to give up. Evolution has solved a lot harder problems than that, and likely our genetic engineers could as well. The solution is changing the DNA, redesigning human physiology for low gravity. while we’re at it, I’m sure we’d want to make a number of other improvements, most of which already exist in the spectrum of human variation.
It would be easy to design in or select for increased intelligence ( av 140) , so that they would be able to learn new tasks more rapidly [ with as few as 5 repetitions !] . While we’re at it, they should also have a built-in willingness to learn, and an eagerness to have a purpose. They should be curious – and stronger than typical Terrans#.
Although there would be variation within this new population, they would have significant average phenotypic differences from every Earth population. On any given trait ( other than tolerance for low gravity) there would be some overlap with existing human populations, although perhaps not very much in some traits ( like intelligence).
But, although instantly recognizable, significantly different in genome and phenotype, and many ways quite formidable, those Martians would not be a different race. Why?
Because Carl Zimmer and David Reich have recently discovered, a population isn’t really a race – not matter how different – unless it’s been around a long, long time. Five thousand years isn’t nearly enough. Previous definitions of races or subspecies never mentioned this, so it must be a new discovery.
And by the same inexorable argument, German Shepherds, developed in 1899, do not exist. There is no such breed. I wish this had been generally known back when I had a paper route, because if I had just known that the beast on my Sunday route didn’t really exist, either he wouldn’t have bitten me or at minimum it would have hurt less.
# And have highly mobile ears.