On Monday, Feb. 21, Saltzman presented her findings as part of an eight-member panel titled Comparative Perspectives on Brain and Behavior at the annual meeting of the American Association for the Advancement of Science in Washington D.C. On March 10, the BBC aired an interview with Saltzman by Geoff Watts of the BBC 4 radio show "Leading Edge" on the links between dominance in female marmosets and their fertility. Saltzman's findings show that subordinate females fail to ovulate, becoming infertile.
Saltzman's marmoset research, conducted at the University of Wisconsin, touches on the interactions among hormones, the brain and behavior. In many species, interactions with social partners can profoundly affect an individual's reproductive functioning. Among primates, the social regulation of fertility is especially pronounced in the marmosets and tamarins, New World monkeys in which socially subordinate females often remain infertile and sexually inactive until they become dominant.
Researchers think this hormonally-mediated change benefits the subordinate females, because even though these monkeys will not be passing along their genes, they will be helping to rear closely related infants.
When subordinate females do breed, their infants are likely to be killed by the dominant female, Saltzman and her colleagues have recently found. So, by switching off their fertility, subordinate females may avoid investing significant resources in infants that aren't likely to survive. Fertile marmosets usually have twins twice a year and need a lot of help from their family group to successfully rear their young.
"What's most exciting is learning how the social environment can profoundly affect an individual's fertility," she said. "This is an excellent model system for studying this issue."
According to Saltzman, understanding these mechanisms can advance the understanding of the social regulation of fertility in humans and other animals.
Related links
Wendy Saltzman's faculty Web site in the Department of Biology: http://biology.ucr.edu/people/faculty/Saltzman.html
AAAS Press release on the Web at: http://www.eurekalert.org/pub_releases/2005-02/aaft-app021205.php
BBC 4 Radio's Leading Edge: http://www.bbc.co.uk/radio4/science/leadingedge.shtml
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