WHEN ARE PERIPHERAL-POPULATIONS VALUABLE FOR CONSERVATION

A great deal of effort is spent protecting geographically peripheral p opulations 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 geneti c divergence from other conspecific populations. Peripheral population s 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 populatio ns. The long-term conservation of species is likely to depend upon the protection of genetically distinct populations. In addition, peripher al populations are potentially important sites of future speciation ev ents. Under some circumstances, conservation of peripheral populations may be beneficial to the protection of the evolutionary process and t he environmental systems that are likely to generate future evolutiona ry diversity.