Oct. 26, 2004 — The journal Nature Genetics published online a special issue on Tuesday Oct. 26 dealing with the question of what we consider “race” and how it relates to genetic differences and similarities among humans.

The articles in Nature Genetics deal with a controversial idea that has emerged in recent years as geneticists have studied the genes of people around the world, namely, that what we consider “race” — skin color and certain other physical characteristics — is not necessarily reflected in our genes. For example, in some cases a white person and a black person may be more closely related genetically than two black people.

One article in the special issue was written by University of Utah geneticists Lynn B. Jorde and Stephen Wooding. Here are some comments from Jorde summarizing their paper:

“There are not well-defined boundaries that would distinguish one race from another at the DNA or gene level because there is a lot of overlap between populations in terms of their genetic variation,” he says. “For instance, we find African genes in people who are considered Scandinavian, and we find English genes in people who are considered Chinese.”

Jorde adds: “There is no such thing as a genetically ‘pure’ population. Because of our constant pattern in history of migration, we all share genes.”

“We are not saying there are no differences between populations or so-called ‘races,’ ” he says. “We are saying that that while there are differences on average, there is so much overlap and so much sharing of genetic variation that you can make serious mistakes if you try to infer something about an individual patient based on his or her racial background.”

For example, “we know that sickle-cell disease is much more common in persons of African descent. But that doesn’t mean a European can’t have sickle-cell disease. That too reflects the pattern of migration and sharing of genetic variation.”

A longer, lay-language explanation of the emerging view of race and genetics was published in the December 2003 issue of Scientific American magazine. The article by University of Utah physician-geneticist Michael J. Bamshad and science writer Steve Olson was titled “Does Race Exist?”