Colleagues - Illustrious Dr. Joel Peck (from Maynard Smith's mafia) will give a talk titled ALTRUISM AND SEX on Wednesday, October 4th, at 11:00 in the 6th floor core area seminar room in Building 45 (Natcher). The abstract follows: Group selection can favor altruistic phenotypes. Altruism can evolve in very large demes, but that this process requires a special type of epistasis, 'crossover epistasis', which is only effective in sexual populations. This suggests that sex may favour the evolution of altruism, and suggests a new hypothesis to explain the rapid extinction of asexual lineages. Alex Kondrashov