Demographic and genetic constraints on adaptation

Populations unable to evolve to selectively favored states are constrained. A genetic constraint occurs when heritable variation in selectively favored directions is absent (“absolute constraint”) or present but small (“quantitative constraint”). Quantitative—unlike absolute—constraints are presumed surmountable given time. This ignores that a population might go extinct before reaching the favored state, in which case demography effectively converts a quantitative into an absolute constraint. This talk will describe models of demography and evolution that yield formulas for predicting when such conversions occur.