%0 Journal Article %A Richard Chin %T Senescence as a defense strategy against parasites %D 2017 %R 10.1101/143362 %J bioRxiv %P 143362 %X The teleology of aging has been one of the more vexing and controversial question in biology. While the prevailing view of aging as a non-programmed, degenerative process has been challenged by recent discovery of genes that appear to influence the rate of aging and of interventions such as parabiosis and microbiome transfers that appear to reverse some features of aging, a convincing explanation for why programmed senescence might be evolutionarily favored has been lacking.1,2,3,4,5 Here we describe stochastic simulations of host and parasite populations with senescence as an independent variable. The results show that populations with more rapid senescence bear lower parasite loads and oscillate more quickly through alternate phenotypes with differential resistance against parasites. We conclude that programmed aging and death may promote host evasion of parasites in a co-evolutionary competition against parasites. %U https://www.biorxiv.org/content/biorxiv/early/2017/05/29/143362.full.pdf