Pinguin is right. It would be silly to deny that families share genetic characteristics: the whole science of DNA classification depends on it. And families intermarry among local families - especially until the arrival of modern transportation.
So you get genetically distinct families, clans, tribes, races, simply arising from the difficulty of moving from one place to another. In Africa, with the considerable physical barriers to inter-group mixing, and the much longer history of human occupation, you of course get far more differences between groups than you do in the rest of the world. So there are more different races in Africa than outside it.
To talk about there being three basic races, caucasoid, negroid and mongoloid is of course outdated nonsense on a par with believing in a flat earth.
Edited by gcle2003 - 18-Aug-2007 at 06:22