Evolutionary geneticist, Dr. Richard Lewontin, speaks at the Hitchcock Lectures at UC Berkely on race and genetics, the effects of migration, invasion, conquest and subsequent rape.  He asserts that race is a “social reality” but not a biological reality, that there is no single gene that differentiates one so- called race from another.  Lewontin says, “We don’t know of any gene that is race- distinguishing.”  He also demonstrates the difficulty of assigning persons to races due to language and migration.  It is a brilliant presentation.