Demography and the Age of Rare Variants

Demography and the Age of Rare Variants

In this paper we describe a method for estimating the age of rare genetic variants. These ages are highly informative about the extent and dates of connections between populations. Variants in closely related populations generally arose more recently than variants of the same frequency in more diverged populations. Therefore, comparing the ages of variants shared across different populations allows us to infer the dates of demographic events like population splits and bottlenecks. We also see that rare functional variants shared within populations tend to have more recent origins than nonfunctional variants, which is consistent with the effects of natural selection.