"In 1942, the anthropologist Ashley Montagu published 'Man’s Most Dangerous Myth: The Fallacy of Race,' an influential book that argued that race is a social concept with no genetic basis...."

"Beginning in 1972, genetic findings began to be incorporated into this argument.... In this way, a consensus was established that among human populations there are no differences large enough to support the concept of 'biological race.' Instead, it was argued, race is a 'social construct,' a way of categorizing people that changes over time and across countries. It is true that race is a social construct. It is also true... that human populations 'are remarkably similar to each other' from a genetic point of view. But over the years this consensus has morphed, seemingly without questioning, into an orthodoxy.... The orthodoxy goes further, holding that we should be anxious about any research into genetic differences among populations.... I have deep sympathy for the concern that genetic discoveries could be misused to justify racism. But as a geneticist I also know that it is simply no longer possible to ignore average genetic differences among 'races.' Groundbreaking advances in DNA sequencing technology have been made over the last two decades.... I am worried that well-meaning people who deny the possibility of substantial biological differences among human populations are digging themselves into an indefensible position, one that will not survive the onslaught of science.... It is important to face whatever science will reveal without prejudging the outcome and with the confidence that we can be mature enough to handle any findings. Arguing that no substantial differences among human populations are possible will only invite the racist misuse of genetics that we wish to avoid."

From "How Genetics Is Changing Our Understanding of 'Race'" by Harvard genetics professor David Reich (NYT).