Seminar – Parental age effects and the evolution of senescence
Rob Laird, Associate Professor, Department of Biological Sciences, University of Lethbridge
Senescence (‘aging’) is the progressive physiological deterioration in individuals, resulting in decreased survival and reproduction in advanced age classes. Evolutionary theories of senescence stem from the idea that the force of natural selection wanes with age—both because few individuals live to advanced age classes even in the absence of senescence, and because early reproduction contributes disproportionally to future generations. Interestingly, this argument applies equally to a potential ‘third component of senescence’: Along with reductions in survival and reproduction, we also expect diminished offspring quality with increasing parental age. I will summarise our empirical results on these ‘parental age effects’, use them to motivate theoretical extensions of traditional population projection matrices, and discuss their contribution to the evolution of senescence.