America's modern struggle with race has proceeded on three fronts. The legal battle effectively ended a half-century ago with the Civil Rights Act of 1964. The second front, the battle against private prejudice, has not been won so decisively, but the experiences of Cliven Bundy and Donald Sterling in the past few weeks confirm a longstanding truth about American society: Expressions of racial prejudice by public figures are punished swiftly and severely.

The third front is different in kind. This campaign is waged not against actual violations of civil rights or expressions of prejudice or hatred, but against the idea that biological differences among human populations are a legitimate subject of scholarly study. The reigning intellectual orthodoxy is that race is a "social construct," a cultural artifact without biological merit.

The orthodoxy's equivalent of the Nicene Creed has two scientific tenets. The first, promulgated by geneticist Richard Lewontin in "The Apportionment of Human Diversity" (1972), is that the races are so close to genetically identical that "racial classification is now seen to be of virtually no genetic or taxonomic significance." The second, popularized by the late paleontologist Stephen Jay Gould, is that human evolution in everything but cosmetic differences stopped before humans left Africa, meaning that "human equality is a contingent fact of history," as he put it in an essay of that title in 1984.

Since the sequencing of the human genome in 2003, what is known by geneticists has increasingly diverged from this orthodoxy, even as social scientists and the mainstream press have steadfastly ignored the new research. Nicholas Wade, for more than 20 years a highly regarded science writer at the New York Times , has written a book that pulls back the curtain.