Far into the future, humanity is largely split into 2 groups.
- The first group consists of space-dwelling humans, who live in enormous space stations equipped to sustain human life indefinitely, getting their resources from asteroids and small moons.
- The second group consists of planet-dwelling humans, who live lives very similar to those we live today.
The planets that these humans inhabit are entirely Earth-like, so I don't expect much evolutionary change for the planet-dwellers. However, I'm curious as to how millennia in space might affect humans from an evolutionary standpoint.
I'll try to give as much detail as possible as to what life is like for these space-dwelling humans.
Most people live on large space stations, and, when I say large, I mean they average Manhattan-sized, with a similar population density (although there will be much larger "Super Stations" and much smaller stations). The living quarters of these stations are equipped with artificial gravity. The personal quarters of individuals is typically the size of a small apartment, although wealthier individuals can, of course, purchase themselves larger compartments.
Although the living quarters are equipped with artificial gravity, working and living in 0g is something that occupants deal with on a daily basis on industrial spacecrafts (such as haulers and mining craft) and in industrial areas of the space station.
Occupants mainly subsist on genetically altered algal oil that is designed to provide all necessary nutrition, however "real" food does still exist as a luxury product that you can buy as a special treat now and again. Water is produced by a combination of ice mining and synthesizing oxygen(produced as a biproduct of algal production) and hydrogen(harvested from nearby stars), and is recycled very efficiently (nearly 97%!).
The technology level of these civilizations is incredibly advanced: cybernetic enhancements are commonplace. Poverty still exists, but in a different form: no one goes hungry because food production is simply a bi-product of oxygen production. Instead, the poor are "poor" because they are denied luxuries such as enjoyable living quarters, cybernetic implants, and "real" food.
Over the course of hundreds of thousands of years, how might these humans evolve in their new environment, far away from the conditions that they had originally evolved in?