Explore the fascinating world of sex allocation in this 48-minute lecture from Yale University's Principles of Evolution, Ecology and Behavior course. Delve into the complex decision-making process organisms use to distribute their reproductive investment between male and female functions or offspring. Examine the optimal 50:50 ratio and the circumstances that can alter it. Investigate how sex allocation influences sequential and simultaneous hermaphrodites, and learn about species that can control their offspring's sex ratios based on environmental conditions. The lecture covers key concepts including the Shaw-Mohler principle, male-female fitness equivalency, sex ratios in various contexts, and sex assignment in offspring. Gain a comprehensive understanding of this crucial aspect of evolutionary biology and its implications for reproductive strategies across different species.