Quantitative Genetics of Life History in a Population of Long-Lived Reptiles


Meeting Abstract

P3-78  Sunday, Jan. 6 15:30 – 17:30  Quantitative Genetics of Life History in a Population of Long-Lived Reptiles HOEKSTRA, LH*; JUDSON, JM; JANZEN, FJ; BRONIKOWSKI, AM; Iowa State University; Iowa State University; Iowa State University; Iowa State University lhoek@iastate.edu

Comparative studies of the evolutionary genetics of complex traits remain limited by sparse taxonomic sampling of natural populations, particularly for life-history traits, such as lifespan and lifetime reproductive fitness, that require sampling the full life course of individuals. Not surprisingly, most existing estimates of the inheritance of such life-history traits come from model organisms in laboratory settings (e.g., flies, mice) or from species of particular interest to humans (e.g., humans, horses, dogs, birds). However, recent advancements in genomic sequencing and new methods for inferring wild pedigrees allow the development of non-traditional model systems. The Western painted turtle, Chrysemys picta, is an excellent candidate for studying the quantitative genetics and life-history evolution of a long-lived ectothermic vertebrate. As with many turtles, painted turtles lack sex chromosomes, yet still exhibit a suite of sexually-dimorphic traits throughout their lifetime. Extensive mark-recapture and census efforts of a wild population of painted turtles along the Mississippi River in Thomson, Illinois have provided sound estimates of demographic parameters, including sex ratio, vital rates, and heritability of nesting behavior. We leveraged 25 years of tissue samples collected during this longitudinal field study to genotype a large fraction of the population (N=900). We used the resulting genome-wide SNP panel to associate phenotypic variation in life-history traits (e.g., size-at-maturity, reproductive effort, lifespan) with population-genetic variation, addressing key questions about the sex-specific heritability of life history.

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