Chromosomal speciation and the conservation of genetic variability: The case of the genus Ctenomys (Rodentia, Caviomorpha, Ctenomyidae)enomys (Rodentia, Caviomorpha, Ctenomyidae)

BIDAU, C. J.; GIMENEZ, M. D.; CONTRERAS, J. R.

Basic and Applied Genetics

SOCIEDAD ARGENTINA DE GENÉTICA

Lugar: Buenos Aires; Año: 1996 vol. 12 p. 25 - 37

1666-0390

The speciation problem poses two basic questions: 1) How are new species of organisms generated? 2) What is the role of speciation in the evolutionary process? In this paper, the first question is discussed relative to current species concepts and chromosomal speciation is proposed as one of the mechanisms capable of generating rapid reproductive change, in concordance with the proposals of the punctuated equilibria theory (and allow, as a consequence, phenotypic adaptive change without the requirement of protracted geographic isolation and slow divergence). With respect to the second question, the previous considerations lead us to think about speciation as a means of perpetuation of adaptive genetic variation that could be lost through dilution in the case that reproductive isolation does not appear in a locally adapted population. Finally, the processes of chromosomal speciation (without significant morphological differentiation) are considered in relation to the preservation of genetic variability in natural populations.