Evolution in the Anthropocene: Population Genomics of NYC Wildlife
Over 50% of humans now lives in cities, and urbanization is one of the most important drivers of land transformation around the world. Increasingly, human-drive changes such as urbanization or global climate change are also selective forces driving rapid evolutionary change in other species. This presentation describes ongoing efforts to develop white-footed mice (and a few other species) in New York City as models for examining the evolutionary implications of urbanization. We also discuss potential similarities between evolutionary responses to climate change and urbanization. Our lab integrates complementary approaches from landscape ecology, urban ecology, and population genomics. Most recently, we have been using a landscape genomics approach to examine how urbanization structures both neutral and adaptive genetic variation. We have generated high-density, genome-wide SNP (single nucleotide polymorphism) genotypes using RAD-Seq from over 200 mice sampled from 25 populations along an urban-to-rural gradient spanning NYC to rural Connecticut. We are using outlier analyses to identify candidate genomic regions experiencing selection, and spatial approaches to identify SNPs exhibiting a strong frequency threshold along urban-to-rural gradient. We are also examining environmental correlations between SNP frequencies and variables related to urbanization. Preliminary results indicate that spatial models based on relatively few high-contrast landscape variables (e.g. vegetation vs. impervious urban surfaces) explain connectivity between urban-suburban-rural populations. Genomic regions containing coding sequences involved in metabolism, immunity, and reproduction exhibit statistical signatures of selection in isolated urban populations of white-footed mice.