223T Poster - Population Genetics
Thursday June 09, 9:15 PM - 10:00 PM

Authors:
Elissa Cosgrove ¹; Reed Bowman ²; John Fitzpatrick ¹; Andrew Clark ¹; Nancy Chen ³

Affiliations:
1) Cornell University, Ithaca, NY, USA; 2) Archbold Biological Station, Venus, FL, USA; 3) University of Rochester, Rochester, NY, USA

Keywords:
Natural selection

Natural selection is a complex process that can impact multiple stages of the life cycle. Exhaustive enumeration of populations, along with construction of the full population pedigree, opens the opportunity to estimate different selection components and evaluate the role of antagonism in maintaining genetic variation for fitness. Here, we infer the action of natural selection on fitness components using a 25-year genomic, phenotypic, and pedigree dataset in the Florida Scrub-Jay (Aphelocoma coerulescens), a species in rapid decline due to habitat loss. A population of Florida Scrub-Jays at Archbold Biological Station has been studied since 1969, resulting in annual and lifetime fitness measures for thousands of individuals on a 14-generation pedigree. We genotyped every individual in our study population over two decades at 15,416 genome-wide SNPs. To test for selection acting on specific life-cycle stages, we modified existing selection component analysis frameworks to take full advantage of exhaustive population sampling. We used generalized linear mixed models that included kinship and considered tens of potential ecological covariates to test for differences in viability, fecundity, mating success, and overall lifetime reproductive success (LRS). We identified 12 loci under viability or fecundity selection and 5 loci with significant differences in LRS among genotypes. In comparing genome-wide effect size estimates between different fitness components, we observed a strong positive correlation between survival and LRS. We also found a negative correlation between effect sizes for male and female LRS, which may reflect a degree of sexual conflict, and between female lifespan and female fecundity, which may reflect the classic life history trade-off between survival and reproduction. This fine-scale dissection of selection components provides important insights into the role of selection in maintaining genetic variation in a natural population.