Role of temperature in geographic speciation (An example of rodents)

It is demonstrated that the noncoincidence of vectors of geographic variation and alterations of the environmental temperature factor, which contradicts the Bergmann rule, may indicate the presence of a new species. Exterior characters of the new species, in the author's opinion, may be formed by saltation during one generation. It only remains for natural selection to fix the finished form under conditions of long-term stabilization of the changed norm of reaction to a new quality of the temperature factor.