Date of this Version
Evolutionary Ecology Research
Question: How well are genetic benefits hypotheses for extra-pair paternity supported by empirical evidence?
Data incorporated: Almost all published studies testing for genetic benefits from 1980 onwards (121 papers, 55 species).
Analysis methods: Collected key features and findings of each study in a database. Determined overall level of support for both good genes and compatible genes hypotheses. Conducted a formal meta-analysis on a subset of studies asking the following questions: (1) Do extra-pair mates of females have different phenotypes than their within-pair mates? (2) Do extra-pair offspring differ in viability from within-pair offspring? (3) Is there a correlation between the genetic similarity of a social pair and the incidence of extra-pair paternity?
Results: Both the good genes and compatible genes hypotheses failed to be supported in more than half of the species studied. The meta-analysis shows that extra-pair males are on average larger and older than within-pair males, but not different in terms of secondary sexual traits, condition or relatedness to the female. No difference was found between extra-pair and within-pair young in survival to the next breeding season. We found no significant correlation between pair genetic similarity and extra-pair paternity.
Conclusions: Genetic benefits are not strongly supported by available empirical data. New hypotheses are needed.
Akçay, E., & Roughgarden, J. (2007). Extra-Pair Paternity in Birds: Review of the Genetic Benefits. Evolutionary Ecology Research, 9 (5), 855-868. Retrieved from https://repository.upenn.edu/biology_papers/12
Date Posted: 02 October 2015
This document has been peer reviewed.