On Defining Species in Terms of Sterility: Problems and Alternatives

Abstract

Despite its historic role as a criterion of species status, intersterility sensu lato is not an acceptable characteristic for delineating the genetic species or field of gene recombination. This conclusion is not new since it is in agreement with Darwin 's views as expressed in Origin of Species (1859). The critical role of sterility in distinguishing between the prevailing genetic concept of species and its rival, the recognition concept, is demonstrated. Factors that may have led to the general acceptance of Wallace's views on speciation, rather than Darwin's, are briefly discussed.