Earth is also the series's main setting on which the humans live.

First, do humans live longer now I comparison to 2000 years ago?

I think humans in the future will live on Mars.

Perhaps even humans lived, though they must be changed beyond recognition.

So humans weren't living and working according to the Sun any more, but sunlight hadn't gone away.

Climate has a very big effect on the way that humans live.

Humans have lived along the river for approximately 3,000 years.

Cattle and humans usually lived together in the same house.

Most humans at this time did not live in one place, but moved around as the seasons changed.

All these things affect the way that humans live in different parts of the world.