When Are Peripheral Populations Valuable for Conservation?

TLDR

Peripheral populations of widespread species are increasingly protected because they are expected to diverge from central populations through isolation, drift, and selection, and may be crucial for long‑term conservation, future speciation, and evolutionary processes. The study examines when it is worthwhile to allocate resources to protect peripheral populations. The authors assess conservation value by evaluating the genetic divergence of peripheral populations relative to other conspecific populations. Empirical evidence shows that peripheral populations are frequently genetically and morphologically distinct from central populations.

Abstract

A great deal of effort is spent protecting geographically peripheral populations of widespread species. We consider under what conditions it is appropriate to expend resources to protect these populations. The conservation value of peripheral populations depends upon their genetic divergence from other conspecific populations. Peripheral populations are expected to diverge from central populations as a result of the interwoven effects of isolation, genetic drift, and natural selection. Available empirical evidence suggests that peripheral populations are often genetically and morphologically divergent from central populations. The long‐term conservation of species is likely to depend upon the protection of genetically distinct populations. In addition, peripheral populations are potentially important sites of future speciation events. Under some circumstances, conservation of peripheral populations may be beneficial to the protection of the evolutionary process and the environmental systems that are likely to generate future evolutionary diversity.