This lecture, based on a ground-breaking study by one of the greatest evolutionary theorists since Charles Darwin, Robert Trivers, examines the curious case of honor killings, which seem to make no evolutionary sense—why would a father kill his own daughter and thereby eliminate half of his own genes from propagating into the next generation? The answer is to be found in who, exactly, is committing these murders and why. In short, the vast majority of honor killings are conducted by fathers and uncles who murder young women who have been arranged to marry a first cousin but who have fallen in love with someone outside of the family. When Dr. Trivers did the genetic analysis he found his answer. This riveting talk by Dr. Trivers took place in Dr. Michael Shermer’s Skepticism 101 course at Chapman University, filmed on Thursday November 16, 2017. The lecture was followed by Science Salon # 16: a lively conversation on everything from evolutionary theory and human nature to how to win a knife fight and Trivers’ membership in the Black Panthers. Don’t miss this engaging exchange with one of the most interesting scientists of the past half century.