[pelagicAustral]

I do not know for a fact, but I wouldn't think there is a single chance in hell that living in an environment with 1/6th of the gravity we've got on earth would not cause long term effects in your health, specially to the bones and muscle.

[dekhn]

I assume that any large scale colonization of space will involve deeply modified germline humans: reduced oxygen requirements, greater tolerance to radiation, fewer rigid bones, tolerance to many forms of low gravity, loss of ability to live on the surface of a high G planet. And I guess an increased tolerance to boredom given how long it takes to get anywhere when minimizing energy expenditure.

[lawlessone]

Probably fine .. as long as you don't come home.

[uneoneuno]

Also changes eye shape over time, causing vision issues, etc.. Longer you're up there the more starts to go wrong. We were built to fight off gravity. I think its worth considering that it may be fundamentally impossible for humans to reproduce/gestate babies/live entire lifetimes/generations in low gravity conditions.

[ta1243]

Well there's a world of difference between micro-gravity (where there have been problems with nice) and low gravity like on the moon (where there's been no experiments)

If you did have viable babies in low (not zero) gravity situations though, would you in fact be starting a new species.

[gus_massa]

It's not clear when a new specie is different from the previous one, but you probably need:

* Like 100.000 years, probably more. (From the split of us from chimps 5.000.000 I counted like 30 species in https://en.wikipedia.org/wiki/Human_evolution , but the number depends a lot on who count them.)

* Isolate the populations so they can't interbreed (first because they can't meet and later becuse the dna is incompatible)