| That the genetic relationship between parents and offspring makes evolution by natural selection possible is an axiom of modern biological thought. However, relatedness can also impact ecology and evolution through pathways other than the genetic and through relationships other than the parental. Using molecular techniques, I studied alternate effects of relatedness on the ecology and evolution of wood frogs (Rana sylvatica) in the wild. Three different studies were conducted. In the first, I found that larvae were nonrandomly aggregated with their siblings in one pond and nonrandomly dispersed from their siblings in another. According to kin selection theory, the location of an individual with respect to its relatives can have important ramifications for its individual and inclusive fitness. In the second study, I found that the estimated relatedness of parents was negatively correlated with the survival of their offspring in the wild but not in the laboratory. These results suggest that the negative effects of inbreeding are more severe in the wild than in captivity. The third study suggests that females can influence the fitness of their offspring through non-genetic effects. Although these maternal effects are often ignored in measures of selection, I use the example of sexual size dimorphism to show that their inclusion or exclusion can have important consequences for conclusions about evolution. |
