I'm not sure why but look forward to reading other people's answers. The only thing I can think of is that different climates call for different skin types - for example hotter climates tend to have darker skinned people who's skin can handle the intense sun better, and colder climates tend to have people with whiter skin.
There aren't really, because there's no such thing as race. If there was you would be able to definitively say how many races there are and what they are called but actually if you asked a dozen different people that question you would probably get a dozen different answers. Race isn't a genetic thing really, it's an idea, and different cultures and people define it differently. Consider things like the "one drop" law. In some places (like the USA) having "one drop of African blood" (ie. one black ancestor you know of of) makes you black, regardless what you look like), and in others, like in the Carribean, "one drop" makes you white, so the same person could be considered black in one country and white in another without their skin colour changing at all. In Australia whether someone is considered an Indigenous Australian or not depends on whether they identify as one and are accepted by their community as one and not on their skin colour.
As for why there are different colours, that's because of the different amounts of melanin our skin (which also determines hair and eye colour). I suppose it's down to natural selection. Having more melanin helps protect you from sunburn and skin cancer but makes it harder for you to absorb vitamin D so I suppose it'd make sense to gradually (over many, many generations) evolve lighter skin when you lived somewhere like Europe with a lot less sunlight than you get in Africa or Australia. I'm not a scientist though, that's just my understanding of it.
Oh, and then there are redheads who have a mutant type of melanin that gives our hair a different colour and means we freckle instead of tanning. The genes for things like hair colour can be linked to other stuff that you wouldn't expect (for instance some redheads have an increased sensitivity to thermal pain and anaesthetics work differently on them) so the things that govern skin colour might seem quite unconnected.
Oops I meant to add a link.
That's from an interesting tv series about race.
"Much of the program is devoted to discovering why. It examines several discoveries that illustrate why humans cannot be subdivided into races, and reveals that there are no characteristics, no traits - not even one gene - that distinguish all members of one "race" from all members of another.
Humans are among the most similar of all species. That's because modern humans, all of us, evolved in Africa, and began leaving only about 70,000 years ago. As we migrated across the globe, populations bumped into one another, mixing their mates - and genes. Populations have just not been isolated long enough to evolve into separate races, or sub-species.
In a "walk" from the equator to the North, we can see how visual characteristics vary gradually and continuously between populations. There are no boundaries.
We also learn that most traits - be they skin color or hair texture or blood group - are influenced by separate genes and thus inherited independently one from the other. Having one trait does not necessarily imply the existence of others. Skin color really is only skin deep. "
Beauty has always been determined by skin colour. Unfortunately since time unknown, skin colour even determines capability, character, rank and such things. Hopefully a day will come, when racism is eradicated totally.
Interesting that you say that Radika, in times gone by the British used to think the ideal beauty was to have white skin because the rich people didn't have to work in the sun so never tanned and the poorer people were tanned from working in fields. It flipped in more recent times to tanned skin being more ideal as people get a tan when they go on holidays and the rich can afford to do this more often. Of course now we know more about the dangers of sun exposure so I'm sure it will change again.
In Australia I don't think people look so much at the colour of a person's skin as they used to, and we're becoming more used to people from all different countries living together and enjoying the benefits of each other's cultures.
Hi Sarah, you got my name wrong.
This is a very debatable topic, and I don't really want to get into it.
It is a good thing that people are becoming more broad minded. But people with old and 'traditional' views, though numbers reduced, still exist.
According to the documentary series I referenced above judging people by skin colour isn't actually something people have always done. That gives me hope that it isn't something we'll always do, but rather that humanity is just going through a bit of an awkward phase.
Wow, difficult question to answer. I guess when and if the lands were once connected, humans spread out. Then, survival of the fittest dictated what type of human would prevail in any given environment. That, in 2 sentences, is just my guess.
Like Jennifer said, there is no such thing as 'race'. It is a mere construction used to justify discrimination and imperialist agendas. As for the colour of our skin, it is influenced by melanin in our skin.
Only one race exists but the differences in our size shape and color is driven by a range of issues like climate, food supply and genetic dominance from an area.
The genetic issue also has some influence over the stability of a region. I believe that some regions are at war more often than others are because of a genetic based tendency toward violence or an inability to compromise based on a mental disorder. I noticed this with a women that I had a relationship with who was quite violent in nature. She advised to me that her father was a brutal person and she was the same. It seems that we evolve based on genetics, climate and partly social experience.