Question: Why does races exist?

Luke Williams answered on 16 Jun 2016:

It is partly a cultural thing, but the reason we have different amounts of melanin in our skin, for example, is largely a result of where we lived historically.

Europeans lived with relatively low amounts of sun, particularly notable at the very northern reaches, and so needed paler skin in order to get enough vitamin d to live healthily. I think there was also a great deal more forest cover historically too, which would have reduced the sunlight levels even more.

Africa receives an awful lot more sun, and there may have been less cover from forests (fewer trees about), and so needed to protect themselves from excessive UV light, hence darker skin.

It is likely that over time, if we had been completely cut off from each other, then we may have gone on to form entirely different subspecies, or perhaps even different species entirely. That didn’t happen though, there are records from very far in the past which clearly show people traveling great distances.

I think there are a few more differences than just skin colour, but the evidence is pretty weak I think. Examples include alcohol tolerance, ability to drink milk, resistance to diseases and height. Not sure whether the difference is cultural or genetic, and I am not sure there is an answer as the evidence as I said is pretty thin.

Ultimately though it is believed that due to people moving across the world, races may well become a thing of the past. There will be no more distinction in skin colour, the population will become a sort of bronzed colour, similar to Mediterranean I believe.