Abstracts (first author)
The origins of two colour polymorphisms in a wild mammal population
Author(s): Slate J, Feulner PGD, Gratten J, Pemberton JM
In a wild population of Soay sheep, that has been the focus of a >25 year field study, two coat colour polymorphisms are segregating as single locus Mendelian traits. Previously, the underlying mutations have been discovered, and it has been shown that both genes are under selection. However, the age and origins of the polymorphisms were unknown. In this talk, we show that Soay Sheep underwent admixture with more modern breeds in the 1800s, and that both polymorphisms arose through the introgression of domesticated genetic variants into the Soay population. Therefore, the current field site can be regarded as a ‘natural laboratory’ in which wild type and domesticated variants have been competing with one another for over 100 years. It is shown that domesticated variants are not necessarily less fit in the wild. More generally, admixture between domesticated and wild populations may be a common source of genetic variation, capable of providing the material required for evolutionary change and adaptation.