Diet Change, Aging, and Late Life: Adaptation to Novel and Ancestral Foods
Authors:Krupa Bhakta, Bruce Dang, Brandon Kuey, Phuong-May Nguyen, Samantha Quesada, Grant Rutledge
Mentor:Michael Rose, Professor & Director of NERE, Ecology & Evolutionary Biology , University of California, Irvine
In order to study the effects of diet on aging, populations of Drosophila melanogaster that have been adapted to banana food for over 1000 generations, are introduced to two dietary changes- replacement of banana with orange or apple. Before domestication, ancestral flies consumed rotting apples in the wild, whereas the orange food is a novel diet to the flies. By analyzing age-dependent fecundity and mortality, we can determine the effects of dietary change on fitness and “healthspan”. The orange-treated experimental populations had significantly higher mortality rates and lower fecundity rates during younger ages, but not during later ages. These pilot experiments are intended to test the value of these fruit flies as a model system for research on how human diet influences fitness with the adoption of a Paleolithic or hunter-gatherer diet, one that humans were well adapted to over our evolutionary history before the introduction of grains and dairy foods. We have concluded that lower lx * mx (parameters of female fecundity and survivorship) at early ages in populations exposed to novel diet compared to recently established diet was observed with convergence in Kx (evolutionary fitness) at later ages in treatments without yeast supplementation. In addition, lower lx * mx at earlier ages in populations exposed to novel diet compared to recently established diet and long antecedent diet. More analysis and experiments must be completed in order to compare the Kx of banana and apple diets. By applying a novel orange diet to Drosophila melanogaster from an early age on, Hamilton’s theory that the forces of natural selection decline with age may justify the convergence of Kx and mortality rates within all experimental diets.