[Bells]

Hundreds and thousands of years ago, yes brothers and sisters did in some cases get married and have relationships. I'm surprised people didn't know that - it was acceptable back then and of course in some cases considered more respectable because you were keeping genes within your own family. Of course, when I say this was a long time ago, I do mean a long time ago so it wouldn't affect the extent of the family tree people nowadays tend to have - it'd have been much longer before then!

As for why people have different coloured skin...different parts of the world have different climates and sun intensities. After a certain civilisation lives in a part of a world where it's sunny constantly, their skin would as a result turn darker. And then these genes would pass on to children, because the people who would survive to the age to have children would be the ones who have darker skin since they are coping better in the weather conditions as opposed to developing skin problems, perhaps cancers etc. We studied this in Biology last year, also looking at other similar principles e.g. fur colour on animals. So really, we're all the same but as different colonies have moved to different parts of the world, they in turn formed adaptations to suit where they lived. It's not like a random Chinese person appeared in China and so on - at least that's not what we're led to believe; it's a gradual thing in terms of human characteristics, and it makes a lot more sense that way!