December 16, 2019

Physiological mechanisms of lemur life history trade-offs

PIs: Elaine Guevara, Nicholas Grebe, Christine Drea, Virginia Kraus (Duke University)

Fall 2019 Seed Grant in Social and Biological Determinants of Health

Because aging – the physiological deterioration associated with advancing age – curtails an individual’s chances of survival and reproduction, it presents a puzzle to evolutionary biologists. Adding to the enigma of aging is the existence of extreme variation across lifeforms in lifespan and rate of aging, suggesting that aging processes are modifiable. The evolutionary hypothesis that best accounts for the existence of and variation in aging is that it is the outcome of neglect on a cellular level, occurring when organisms must allocate their limited energetic and biochemical resources to activities other than somatic maintenance, such as reproduction. This cellular neglect may manifest as oxidative stress: a failure to adequately prevent or repair cellular damage (i.e., to lipid membranes and DNA), caused by the chemically reactive molecules that are produced during metabolism. Evidence for the causative role of oxidative stress in aging is mixed. We will test the hypothesis that oxidative stress reflects life history and aging by comparing amounts of cellular damage and repair interspecifically, between two species that show different rates of aging, and inter-individually, between animals of different ages and following different reproductive investments. Resolving questions about the cellular mechanisms and accumulated burden of aging is essential for designing regimens to effectively treat degenerative conditions.

| next >