Date of Award
2007
Degree Type
Thesis
Degree Name
Master of Science
Program
Applied Mathematics
Supervisor
Dr. Lindi Wahl
Abstract
Estimating the fixation probability of a beneficial mutation has a rich history in theoretical population genetics. However, fixation probabilities are extremely sensitive to assumptions regarding life history. We develop a “burst-death” life history model which assumes that generation times are exponentially distributed, but the number of offspring per individual is fixed. Using this model, we estimate the fixation probability for populations of constant size, and for populations which grow exponentially between periodic population bottlenecks. We then predict the optimal time at which to impose bottlenecks, maximizing the probability that beneficial mutations occur and are not ultimately lost. We find that the optimal bottleneck time only weakly depends on the selective advantage but depends strongly on the death rate and burst size. Most importantly, the optimal sampling fraction is a constant with respect to these parameters; sampling about 20% of the population will maximize the rate of adaptation.
Recommended Citation
Hubbarde, Jennifer Elizabeth, "A Burst-Death Model for Experimental Evolution: Fixation Probabilities AND OpTIMAL BOTTLENECK TIMES WHEN GENERATION TIMES ARE VARIABLE" (2007). Digitized Theses. 4459.
https://ir.lib.uwo.ca/digitizedtheses/4459