Most scientists will tell you that race has no biological basis—it is, in academic-speak, a “social construct.” But a new book by distinguished journalist Nicholas Wade challenges that assumption, concluding that race is real and human social behaviour is subject to natural selection just like everything else. As the New York Review of Books put it, in its coverage of Wade’s A Troublesome Inheritance: Genes, Race and Human History, there is now a “statistical sense” in which races are real. Scientists can tell, based on genetic variance, which continent a DNA sample comes from. That might not sound revolutionary to...