Diane M. Doran-Sheehy

Department of Anthropology
Stony Brook University

The evolution of non-conceptive mating: New insights from studies of wild western gorillas

Friday, September 11, 2009
Lecture Hall 2, 4:00 PM

Abstract

Human females, unlike most mammals, are sexually active when conception is not possible. This decoupling of sexual behavior from its conceptive function has had an enormous impact on human social relationships, and yet we know little about the evolutionary significance of non-conceptive mating. Although most non-human mammal females mate only at or around the time of ovulation, some monkeys and apes, including gorillas, also mate outside conceptive periods providing an opportunity to examine when and why it occurs. Here, I examine the function of non-conceptive mating in wild western gorilla females by examining individual variation in the timing and frequency of mating during pregnancy. My results suggest that nonconceptive mating appears to have evolved as a result of female-female competition and not to confuse paternity or to obtain benefits from the male, as previously suggested. These findings indicate that female mating competition is more important than previously considered, and may be a potential factor in the evolution of non-conceptive mating in humans.

Biography

Diane Doran-Sheehy is Professor and Chair of the Anthropology Department of Stony Brook University. She earned her Ph.D. in Anatomical Sciences at Stony Brook University in 1989. Her main area of interest is African Ape behavior and ecology. In pursuit of that goal she is one of the few people in the world who has studied all African apes in the wild, including chimpanzees (Tai Forest, Ivory Coast), bonobos (Lomako, DRC), mountain and western gorillas. After directing the Karisoke mountain gorilla project for two years, she established the Mondika Research Project in 1995 to study western gorillas, the last remaining species of ape that was largely unstudied by humans. Currently she and her students are studying how western gorilla kinship patterns influence behavior between groups, how alterations in the food supply alters gorilla social relationships, and how communication between closely related species varies with differing ecological and social factors. Results of her work are published in various scientific (i.e. Current Biology, Proceedings of the Royal Society B, American Naturalist, etc…) and popular (National Geographic) journals and have aired on Animal Planet and BBC television specials.

Readings

1. Doran-Sheehy, D.M., Fernández, D., and C. Borries (in press). The strategic use of sex in wild western gorillas. American Journal of Primatology.
2. Doran-Sheehy, D.M., Mongo, P. Lodwick, J. and N.L. Conklin-Brittain (in press) Male and female western gorilla diet: preferred foods, use of fallback resources, and implications for ape versus old world monkey foraging strategies. American Journal of Physical Anthropology.
3. Bradley, B.J., Doran-Sheehy, D.M. and Vigilant, L. (2007) Potential for female kin associations in wild western gorillas despite female dispersal.Proceedings of the Royal Society B-Biological Sciences. 274 (1622): 2179-2185.
4. Walsh, P.D., Breuer, T., Sanz, C, Morgan, D. and Doran-Sheehy, D. (2007). Potential for ebola transmission between gorilla and chimpanzee social groups. American Naturalist: 169(5):684-689.
5. Bradley, B.J., Doran-Sheehy, D.M., Lukas, D., Boesch, C. and L. Vigilant (2004). Dispersed male networks in western gorillas. Current Biology 14: 510-513.
6. Lilly, A.A., Mehlman, P.T. and Doran, D.M. (2002) Intestinal parasites in gorillas, chimpanzees and humans at Mondika Research Site, Dzanga-Ndoki National Park, Central African Republic. International Journal of Primatology 23(3): 555-573.
7. Doran, D.M. and McNeilage, A. (1998). Gorilla ecology and behavior.Evolutionary Anthropology 6(4):120-131.