The "recent"-ness of common ancestry (or lack thereof) is what separates you from a Chimpanzee. 80,000 years of evolution matters, so you will find that peoples

The "recent"-ness of common ancestry (or lack thereof) is what separates you from a Chimpanzee. 80,000 years of evolution matters, so you will find that peoples from Europe have many different genotypes and phenotypes from people in Africa (or any other part of the world, for that matter). For example, people in Europe have no incidence of sickle cell disease, a recessive genetic disease that in its heterozygous form grants resistance to malaria. Malaria is not prevalent in Europe, so such a mutation would confer no survival benefit to Europeans as it does in Africans. And indeed natural selection does work so we see no sickle cell disease in Europeans as we do in Africans. Lots of other traits vary across the world, too. Almost all Northern Europeans can digest milk as an adult while few Africans can. West Africa consistently has the fastest runners in the world [1]. It is not hard to take a listing of the single nucleotide polymorphisms (SNPs) in a persons DNA and compare them against a database of genetic sequences from various parts of the world to tell where they came from. The same mutation occurring in parallel in two different populations and persisting is rare enough that you can use SNP data to construct a phylogenetic tree of the human population (here is one I googled up[2]). We can tell interesting things from human population genetics, for example that Amerindians probably came from Asia, since the East Asians are there closest genetic cousins. You should have a mixed-race friend send their spit into 23andMe and see what happens! When races mix, you have genetic admixture. It remains trivial to see which portions of a persons DNA comes from which part of the world because those portions contain SNPs which are only found in certain human subpopulations. If you are the child of an African father and a European mother (like Barack Obama), you get half your chromosomes from your father and half from your mother. A few bits from each chromosome swap over, but it is not hard to unravel which bits came from Africa and which from Europe. The government's big racial categories are somewhat inaccurate (especially hispanic, since some hispanics are European and some are Amerindian). But distinct human genetic populations are very real. Razib Khan's blog[3] is great if you want to move beyond the sound bytes and get into the real science of human population genetics. Sadly, liberal views on race tend to be extremely unscientific. [1] http://www.forbes.com/sites/jonentine/2012/08/12/the-dna-olympics-jamaicans-win-sprinting-genetic-lottery-and-why-we-should-all-care/ http://www.forbes.com/sites/jonentine/2012/08/12/the-dna-oly... [2] http://imgur.com/ZPkTc2C http://imgur.com/ZPkTc2C [3] http://blogs.discovermagazine.com/gnxp/ http://blogs.discovermagazine.com/gnxp/