Intraspecific lineages as focal points in the extinction and persistence of species

A deteriorating environment causes species’ range contraction and places species on a trajectory toward rarity and ultimately extinction. Contraction hypotheses focus on the cumulative demise of single populations or groups thereof, without regard to their evolutionary/genetic affinity. I propose that genealogical lineages, be they referred to as subspecies, ecogeographical races, or otherwise, are focal points in the extinction trajectory of...