Emilee Hart, Doctoral Candidate in Human Evolutionary Biology in the School of Biomedical Sciences won Second Place in the Three Minute Thesis Competition. Her presentation on 'The Color Changing Gibbon" outlined her dissertation research that she is conducting in Dr. Rafaela Takeshita's lab in the Department of Anthropology.
Emilee's 3MT abstract:
Sexual dichromatism is rare among mammals but is most frequently found in the primates, especially in the Hylobatidae taxonomic group also known as the Small Apes. They are a rare and endangered group of primates found in Southeast Asia. The Northern White-Cheeked Gibbon (Nomascus leucogenys) is an example of this sexual dichromatism where the adult males have black fur with white cheeks and the adult females are blonde with black fur around the crown of their head. Did you know that all Northern White-Cheeked Gibbon infants regardless of sex are born blond matching the mother? At around a year old, both sexes will turn to that typical black fur color pattern with the white cheeks seen in the adult males. Emilee’s dissertation research examines the endocrine life history of these gibbons and I hypothesize that these color changes are caused by hormones, specifically DHEAS.
Humans, and many other primates like these gibbons, have the typical sex hormones such as estrogen and testosterone that derive from the gonads, but primates also have a certain amount of adrenally derived sex hormones. In the primate adrenal, there is a mutation that has resulted in the adrenal production of this pro-hormone, DHEAS, which then goes on to convert into those adrenally derived sex hormones. How is this all related? Well, in development there are two developmental stages of the adrenal gland that produces this DHEAS. This development and activation of the adrenal gland is also known as ‘adrenarche’ and has only ever been identified in the Great Apes including humans so far, but Emilee believes delayed adrenarche is also present in Lesser apes.
