Publication Date

Summer 7-15-2020


Life history theory posits the evolution of sex-biased traits through asymmetries in the costs of reproduction. The research presented here evaluated the downstream effects of sex-biases in two age-related disease profiles: tooth loss, in which females exhibit a higher disease burden, and melanoma, in which females have a survival advantage.

Among the Tsimane, a natural fertility population of forager-horticulturalists with a high lifetime fertility and no access to oral healthcare, females lose more than males and around half a tooth per child. Parity accounts for 1.2\% of variation in tooth loss within females, but no variation in tooth loss in males. We conclude that teeth are not a major cost of female reproduction in Tsimane females.

Despite their poorer overall prognosis relative to females, late-stage and metastatic melanoma tumors in males have a higher tumor mutational burden than females. Here we show this relationship extends to early stage primary tumors. Males are likely to have high TMB when compared to females, despite a poorer overall prognosis.

The two studies presented here will help us better understand the role of sex in melanoma and tooth loss. They are important steps in towards a better understanding of the role of sex in disease.


Sex differences, Melanoma, Tooth loss, Costs of reproduction

Document Type




Degree Name

Evolutionary Anthropology

Level of Degree


Department Name


First Committee Member (Chair)

Jeffrey Long

Second Committee Member

Osbjorn Pearson

Third Committee Member

Marianne Berwick

Fourth Committee Member

Hillard Kaplan

Fifth Committee Member

Li Luo

Sixth Committee Member

Joe Alcock

Included in

Anthropology Commons