Mars is inhabited by what I assume are humans that migrated to the planet, but why do they all look Asian? Did they evolve that way over time or was the population that migrated there largely Asian?
The people from Mars that are constantly seen are Amy Wong and her family. Her dad is extremely rich and own half of Mars. If you remember the episode where Fry goes back to college you will notice that there are a variety of cultures on Mars. So to answer your question it is just the population that moved there not really an evolution.