About Dr Nancy Chen
Dr Chen's lab seeks to understand the evolutionary processes that shape patterns of genetic variation over contemporary timescales. She combines genomics with extensive pedigree data from long-term demographic studies to answer questions in evolutionary biology and conservation genomics.
Tracking short-term evolution in a pedigreed wild population
There are now many beautiful examples of phenotypic evolution on ecological timescales. Nevertheless, technological challenges and limited availability of temporal genomic data have left a large gap in knowledge of short-term evolutionary dynamics at the genomic level. Indeed, measuring evolution of natural populations in real-time remains challenging, and systems with sufficient data to study contemporary genetic evolution are rare. Here, we investigate the evolution of natural populations on short timescales using a 25-year genomic, phenotypic, and pedigree dataset in the Florida Scrub-Jay. Using gene dropping simulations, we quantify the expected genetic contribution of recent immigrants and identify large allele frequency shifts due to gene flow or selection. We model the relative roles of different evolutionary processes in shaping patterns of genetic variation genome-wide. Finally, we identify a few loci under selection on specific life-cycle stages. Together, this work shows how knowledge of the pedigree of a population provides the ability to observe directly the actual processes underlying allele frequency change.