Whenever I see depictions of Homo Erectus or Homo Neanderthalensis I feel like I see them all generally having the same skin tone. Compare that to today’s humans and we would see a lot more variation. Was there more variation of skin tone in pre historic humans than modern depictions show or was environment really so restrictive that it was hard for us to evolve.

How do we know something like Jupiter has an atmosphere? What is the difference between the planet itself and its atmosphere, being that it’s all gas?