An evolutionary perspective on genetic load in small, isolated populations as informed by whole genome resequencing and forward-time simulations.

Small populations are vulnerable to increased genetic load and drift that can lead to reductions in fitness and adaptive potential. By analyzing 66 individual whole genomes of Montezuma Quail (Cyrtonyx montezumae) from multiple populations, we illustrate how genetic load is dynamic over evolutionary time. We show that Montezuma Quail are evolving like a ring species, where the terminal extant populations from Arizona and Texas have been separated for ~16,500 years.