This week we welcome Karl Grieshop.
Broad evolutionary implications for sex-specific selection
Males and females of sexually reproducing species must use largely the same genome to develop into very different organisms that accrue fitness in fundamentally different ways. Inevitably, some of the loci underlying fitness experience sexually antagonistic (SA) selection, where alternative alleles have opposite fitness effects in males versus females. Under some conditions, SA selection can maintain stable polymorphisms for fitness, and explain a large proportion of the heritable genetic variance in fitness that we observe in nature. One of these conditions is sex-specific dominance (where the allele that benefits a given sex is also dominant in that sex), which is theoretically inevitable for loci under SA selection, but empirical tests are nearly lacking. I will present evidence for sex-specific dominance of the SA genetic variation for fitness being a strong and widespread phenomenon throughout the genome of a well-characterized seed beetle population. I will then walk through a series of studies on that same population, showing how SA genetic variation influences life history trait variation, population growth, adaptation, inbreeding depression, and mutation load. Results will be discussed in terms of their implications for our understanding of evolution, wildlife management and public health.