system
Given the following post, respond as if you're commenting on Reddit:
human
[40k] So, uh, what happened to all the black people?

Or the indian people for that matter, and what led to asians being relegated to one world of note?
gpt
Think of it this way.  We spend how much of our lives cramped up in bomb shelters, fleeing emperor knows what in spaceships?
 
We know we used to be more of a light brown as everything mixed, and the various localized skin tones and features blended together.
  
But spending so much time indoors, in mines or in spaceships away from sunlight made out skin lighter over time, so that our bodies could take advantage of what sunlight we can get.