Seeing the forest through the seeds: Mechanisms of primate behavioral diversity from individuals to populations and beyond.

Understanding the evolution of primate behavioral diversity requires multilevel approaches that encompass individuals, populations, and the effects of individuals and populations on each other. At one level are analyses of individual behavior patterns under different ecological and demographic conditions. At another level are the effects of individual behavior on the demography and genetics of local populations, which in turn shape the behavior and biology of their individual members. Multilevel studies across populations and over time provide insights into the range of behavioral variation that particular species can express and are necessary for distinguishing the species-specific behavior patterns on which evolutionary comparisons are based. These studies therefore provide the insights necessary to incorporate intraspecific variation into comparative models.