title: [Gradualism or punctualism: data on genetic differentiationof small mammals from the Holarctic region].
abstract: Genetic differentiation of taxa from three Holarctic and three originally Afrotropical phyla of small mammals was analyzed. Its extrapolation to the time scale revealed the following trends: (1) Distributions of fixed gene differences along the scale are relatively independent. (2) Extrapolation of these distributions to the time scale shows that the speciation process is discontinuous. It consists of relatively stable periods interrupted by speciation bursts. (3) Periods of speciation activity in different phyla coincide. In general, these results are consistent with the concept of punctuated equilibria and suggest that the speciation process is temporally discontinuous.
authors.forename: S V
authors.initials: SV
authors.lastname: Mezhzherin
mesh_terms: D000818:Animals; D001110:Arctic Regions; D005828:Genetics, Population; D008322:Mammals / Q000235:genetics*; D010802:Phylogeny; D012641:Selection, Genetic; D013045:Species Specificity; D013997:Time Factors; D014329:Tropical Climate