Journal
JOURNAL OF HEREDITY
Volume 105, Issue 4, Pages 457-465Publisher
OXFORD UNIV PRESS INC
DOI: 10.1093/jhered/esu024
Keywords
defensin; genetic drift; heterozygote advantage; polymorphism; predation
Categories
Funding
- Ullman Professorship
- National Science Foundation [DEB-0613730, DEB-1021397, DEB-1245373]
- Yellowstone National Park
- Division Of Environmental Biology
- Direct For Biological Sciences [1245373] Funding Source: National Science Foundation
Ask authors/readers for more resources
There is a striking color polymorphism for wolves in the Yellowstone National Park where approximately half the wolves are black. The genetic basis for this polymorphism is known, and fitnesses of the genotypes are estimated. These estimates suggest that there is strong heterozygote advantage but substantial asymmetry in the fitness differences of the 2 homozygotes. Theoretically, such fitnesses in a finite population are thought to reduce genetic variation at least as fast as if there were no selection at all. Because the color polymorphism has remained at about the same frequency for 17 years, about 4 generations, we investigated whether this was consistent with the theoretical predictions. Counter to this general expectation of loss, given the initial frequency of black wolves, the theoretical expectation in this case was found to be that the frequency would only decline slowly over time. For example, if the effective population size is 20, then the expected black allele frequency after 4 generations would be 0.191, somewhat less than the observed value of 0.237. However, nearly 30% of the time the expected frequency is 0.25 or greater, consistent with the contemporary observed frequency. In other words and in contrast to general theoretical predictions, because of the short period of time in evolutionary terms and the relatively weak selection at low frequencies, the observed variation and the predicted theoretical variation are not inconsistent.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available