What metric is mentioned as a common way to quantify genetic divergence when analyzing the range structure of species like *C. inclusum*?
Pairwise Fst values
When scientists analyze the genetic variation across the broad geographic distribution of a species to understand its dispersal and isolation history, specific statistical measures are employed. A common metric used to quantify the degree of genetic differentiation between separated populations is the pairwise Fst value. This calculation measures the proportional reduction in heterozygosity due to population subdivision, essentially providing a numerical value indicating how genetically different two populations are from one another based on their shared genetic markers. By overlaying maps of genetic divergence calculated using Fst values onto geographical distribution maps, researchers can hypothesize where ancient dispersal barriers, such as major rivers or mountain ranges, have historically limited gene flow.
