Evidence of hybridization in the Argentinean lizards Liolaemus gracilis and L. bibronii (Iguania: Liolaemini): an integrative approach based on genes and morphology.

OLAVE, M.; L MARTINEZ,; AVILA, L.J.; SITES, JR. J. W.; MORANDO, M.

MOLECULAR PHYLOGENETICS AND EVOLUTION

ACADEMIC PRESS INC ELSEVIER SCIENCE

Año: 2011 vol. 61 p. 381 - 391

1055-7903

The lizard genus Liolaemus is endemic to temperate South America and includes more than 225 species. Liolaemus gracilis and L. bibronii are closely related species that have large and overlapping geographic distributions, and the objective of this work is to further investigate the L. bibronii–L. gracilis mtDNA paraphyletic pattern previously detected, using an integrative approach, based on mtDNA, nuclear DNA and morphological characters. We identified eight morphological L. bibronii introgressed with L. gracilis mtDNAs, and the reciprocal for one L. gracilis, from six localities in the region of sympatry overlap. The morphological identity of these introgressed individuals was confirmed by diagnostic nuclear markers, and this represents the first  well-documented case of interspecific hybridization in the lizard genus Liolaemus. Of the three most likely hypotheses for these observed patterns, we suggest that asymmetrical mtDNA introgression as a result of recent or ongoing hybridization between L. bibronii and L. gracilis is the most likely. This may be due to size selection by L. gracilis female preference for the larger L. bibroni males insympatry, but this requires experimental confirmation.