Genetic variation in nuclear and mitochondrial markers supports a large sex difference in lifetime reproductive skew in a lekking species

• Published in: Ecology and Evolution
• Main Authors: Verkuil, Yvonne I., Juillet, Cedric, Lank, David B., Widemo, Fredrik, Piersma, Theunis
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2014
• Subjects: Effective population size; Philomachus pugnax; ruff; sexual selection; shorebirds; Ruff
• Online Access: https://hdl.handle.net/11370/bfa8e7c9-5ad4-44e9-8125-84c93d28b539; https://research.rug.nl/en/publications/bfa8e7c9-5ad4-44e9-8125-84c93d28b539; https://doi.org/10.1002/ece3.1188; https://pure.rug.nl/ws/files/17409203/Verkuil_et_al._2014_Ecology_and_Evolution.pdf

Sex differences in skews of vertebrate lifetime reproductive success are difficult to measure directly. Evolutionary histories of differential skew should be detectable in the genome. For example, male-biased skew should reduce variation in the biparentally inherited genome relative to the maternally inherited genome. We tested this approach in lek-breeding ruff (Class Aves, Philomachus pugnax) by comparing genetic variation of nuclear microsatellites (θn; biparental) versus mitochondrial D-loop sequences (θm; maternal), and conversion to comparable nuclear (Ne) and female (Nef) effective population size using published ranges of mutation rates for each marker (μ). We provide a Bayesian method to calculate Ne (θn = 4Neμn) and Nef (θm = 2Nefμm) using 95% credible intervals (CI) of θn and θm as informative priors, and accounting for uncertainty in μ. In 96 male ruffs from one population, Ne was 97% (79–100%) lower than expected under random mating in an ideal population, where Ne:Nef = 2. This substantially lower autosomal variation represents the first genomic support of strong male reproductive skew in a lekking species.