Nicholas Wade's "Before the Dawn" is a good roundup of current knowledge in the field, combined with linguistic analysis.

Other terms that are scientifically vague but colloquially useful include gender identity, age, talent, political alignment, and ethnicity. It is good to point out the less-than-rigorous basis for casual categories, but they are used by most and can't be ignored.

And it is especially risky to emphasize quantitative distinctions, since they can be used to show we share well over 90% of our DNA with most species. Genetic arguments also can be used to show that African-ethnic-group ancestry correlates with wider genetic variation. (This is used to explain greater representation at the extremes of physical size and talent.) It also means an older, originating group. The risk here is that it could be used to emphasize a less-evolved character. So it is a double-edged sword, or in a more useful analogy, it's a gun that can point more than one way.

Let's leave genetics to the geneticists. I think a better argument against discrimination is that many, perhaps most, of us have very recent admixtures of African ancestors, i.e. intermarriage or out-of-wedlock relations in our family history. In this country it's common to be much closer than 2000 generations removed---more like four or five---from African roots.

Since Obama considers himself (colloquially) black, to acknowledge how the rest of the country tends to view people like him, we can accept the category.

And it is here:
http://www.bradshawfoundation.com/journey/

Absolute refutation of intelligent design is right here:

There IS NO RACE GENE. We are ONE species,

The scientist changes his theories to fit the the data.

The bigot changes the data to fit his beliefs.

A race is not a species. When Darwin wrote of races of butterflies or even plants, he was apparently speaking of species. The definition of species had not yet evolved [no pun intended].

The denial of race is as destructive and unscientific as the mirror image of the claim of the superiority of race. Both spring from the same primitive fears of science.

Would you prefer to talk of mutants rather than races, BevD? Would that be more satisfying to you for some reason? Would that prove that geneticists are bigots and that your theology is divine?

There are still no white mutants, BevD, nor black mutanss. There are only mutants. Better? Or would you insist yet, like Chris Matthews or Tim Russert or Mark Penn, that there are white mutants and black mutants?

What there are in fact are races that have been isolated over time or space and carry mutated genes that separate them from other races.

Each of us is the result of admixtures of races.

Too horrid to contemplate, BevD, that you carry genes of those "other people?" Not so bad. Try to get over it. Some people are proud of their ancestry but it is just a fact rather than something to take pride in.

Last year, Professor Peter Fine at Florida Atlantic University had an idea for an art class. He would gather a group of students to produce work around their idea of their racial identity. But as part of the class he asked them to take a DNA test that would break down their racial background. His bet was that most of the class - of whom the majority saw themselves as whites of European descent - had no real idea who they were.

He was right. Of 13 students, only one turned out to be completely European. The rest displayed a mixture of European, Native American, African and Asian genes. The one black student turned out to be 21 per cent white. Fine himself - who admits to looking like a corn-fed stereotype of a white Midwesterner - discovered he was a quarter Native American. 'I honestly think these tests could have a large effect on American consciousness of who we are. If Americans recognise themselves as a mixed group of people, that could really change things,' he said.

Fine has a point. For centuries, America has been less a racial melting pot and more a stew, where different communities bump up against each other, but keep mostly to themselves. Yet, as millions of Americans take DNA tests, they are discovering a surprising truth: America's strict racial lines are, in fact, blurred. One-third of white Americans, according to some tests, will possess between two and 20 per cent African genes.

http://www.guardian.co.uk/world/2007/jul/15/usa.genetics

I am planning a business venture to offer multi-colored sheets to the KKK. Perhaps I could offer you and loki some, BevD? It might help with your problems. You are one of those mutants that you deny exist.

Best, Terry

The above comment was addressed to "Terry." I'm sure everyone knew that, though! ;^}