I hesitate to re-enter an area of discussion which, given my own intrepid experience of trying to foment a sane discussion of The Bell Curve over a decade ago, you'd think I'd know to avoid by now. But I find it fascinating, and one of the areas in which science is, I believe, going to challenge many assumptions of right-thinking liberalism. The comments of Richard Watson have revived discussion of the subject and you can find the conventional left-liberal view here, echoed by Crooked Timber. In general, when I read scientific accounts that include passages like the following, my eyes roll when they don't glaze over:

While acknowledging that science is often used for positive purposes, including ones that benefit communities of color, social justice advocates must remain vigilant. All technologies, including new genetic technologies, develop in a political, economic and social context, says Patricia Berne of the Center for Genetics and Society, a public affairs nonprofit based in Oakland, California. "The broader political left has not really grappled with the ways these technologies affect our claim to resources, our claim to rights, and the well-being of our communities," she notes.

Vigilance? Against science? Who knew? Left-liberals, of course, like the use of DNA to exonerate innocent suspects but they're not so happy when this kind of thing happens:

DNA led to the 2004 conviction of an African American suspected of multiple serial murders in Baton Rouge, Louisiana. Initially, police sought a white suspect, based on eyewitness testimony and the assumption that most serial killers are Caucasian. But the case took a turn when a technology firm, DNA Print Genomics, offered to analyze the sample from the crime scene. Their test concluded that the suspect was "85 percent sub-Saharan African and 15 percent Native American" and therefore medium- to dark-skinned black, not white.

Hold on a minute. If race is entirely a social construct, how can DNA reveal it? The answer, of course, is that it isn't just a social construct all the way down. Our DNA is inherited; and that inheritance has complex patterns. You can, of course, define these patterns any way you like. And crude racial categories are not in any way supported by the data. But sophisticated, subtle DNA differences that can indeed reflect a constellation of factors in a human being can be seen in some respects as a racial category. And we can tell someone's genealogy from their DNA. The best layman's guide to this I've read recently is in a NYT piece two years ago. Check it out. The critical bottom line:

A 2002 study by scientists at the University of Southern California and Stanford showed that if a sample of people from around the world are sorted by computer into five groups on the basis of genetic similarity, the groups that emerge are native to Europe, East Asia, Africa, America and Australasia - more or less the major races of traditional anthropology... The billion or so of the world's people of largely European descent have a set of genetic variants in common that are collectively rare in everyone else; they are a race. At a smaller scale, three million Basques do as well; so they are a race as well. Race is merely a shorthand that enables us to speak sensibly, though with no great precision, about genetic rather than cultural or political differences.

As I've noted, the variations within some of these groups are larger than many of the variations between them. But that race does in some way exist as an essential fact of human nature - that these differences render the assumption of an utterly homogeneous human race bogus - seems to me indisputable. The social and political ramifications of this deserve a different and deeper treatment - as does the IQ discussion as it relates to this. But that race exists in nature seems to me to be as obvious as the fact that genealogy exists in nature. We need vigilance against abuse of the truth, not against the truth itself.