AbstractsBiology & Animal Science

Parental age effects and the evolution of senescence in Lemna minor

by Patrick Barks

Institution: University of Lethbridge
Year: 2015
Keywords: age-related declines; Lemna minor; offspring quality; senescence; 0329; 0719; 0309
Record ID: 2062626
Full text PDF: http://hdl.handle.net/10133/3666


Senescence is characterized by age-related deterioration within individual organisms and a resultant decline in rates of survival or reproduction. Such declines seem inherently maladaptive, but occur nonetheless in a wide range of species. My thesis contributes to the questions of (i) why senescence is common in nature, and (ii) why patterns of senescence sometimes vary markedly both within and among species. With respect to why senescence is common, most evolutionary theory on senescence makes the simplifying assumption that all offspring are of equal quality. I show that this assumption does not hold in the aquatic plant Lemna minor, and develop a theoretical model to investigate how age-related declines in offspring quality influence the ‘force’ of natural selection. With respect to variation in patterns of senescence, I describe a common garden experiment demonstrating a high degree of among-population consistency in life expectancy and rates of senescence in L. minor.