title: Genetic and nongenetic mechanisms of speciation.
mesh_terms: D000818:Animals; D005075:Biological Evolution; D003433:Crosses, Genetic; D004463:Ecology; D005260:Female; D005787:Gene Frequency; D005828:Genetics, Population; D006824:Hybridization, Genetic; D007246:Infertility; D008297:Male; D013045:Species Specificity