Date of Graduation


Document Type


Degree Name

Bachelor of Science in Anthropology

Degree Level





Plavcan, Joseph

Committee Member/Reader

Villaseñor, Amelia

Committee Member/Second Reader

Beaulieu, Jeremy

Committee Member/Third Reader

Sakon, Josh


The sexual dimorphism profile of human body composition produces a unique pattern. Compared to other primates, humans have a mild size dimorphism; however, human males have a particularly muscular upper body and human females have a permanent fatty composition. These findings have resulted in varying interpretations related to sexual selection, mating systems, and male competition. Using humerus and femur measurements collected from 9 primate species, we investigated how the pronounced sexually dimorphic tissue composition of humans influences skeletal elements compared to the other primates. We hypothesized that over the course of human evolution, human females developed a body composition that deposits fat while sacrificing muscle levels compared to males, specifically in the upper skeleton. As such, we expected humans to have a higher degree of sexual dimorphism in the upper skeleton than the lower skeleton due to this proposed trade-off. However, the comparative data suggest that regardless of having a pronounced, unique muscle and fat tissue dimorphism, humans exhibit a uniform pattern of sexual dimorphism across the skeleton similar to the other primates.


Sexual dimorphism, primates, body composition, human evolution, fat dimorphism, muscle dimorphism