Synchronized versus asynchronized breeding in cordylid lizards: an evolutionary perspective

Authors


Correspondence

P. le Fras N. Mouton, Department of Botany and Zoology, Stellenbosch University, Private bag X1, Matieland 7602, South Africa. Tel: +027 21 8083227; Fax: +027 21 8082405

Email: pnm@sun.ac.za

Abstract

The lizard family Cordylidae is mainly endemic to southern Africa and comprises 80 named taxa, placed in 10 genera. We mapped parity mode and the timing of gametogenesis in males and females on a genus-level phylogenetic tree for the family, derived from the literature. For those genera for which reproduction data were not available, we investigated male reproductive activity for representative species using museum material. In addition, we constructed an area cladogram to recover ancestral ranges. Our parsimony analysis retrieved two equally parsimonious solutions for evolutionary transformations in parity mode and reproductive timing in the Cordylidae. Both solutions suggest that oviparity and spring gametogenesis in both males and females (synchronized breeding) is the basal condition in the family. The correlated evolution of viviparity and autumn breeding has been noted in many lizard clades, and we therefore prefer the solution suggesting (1) that the transformations from oviparity to viviparity and from spring to autumn gametogenesis occurred simultaneously in the most recent common ancestor of the Cordylinae, and (2) that a subsequent return to spring spermatogenesis occurred in the most recent common ancestor of the Ouroborus-Karusasaurus-Namazonurus-Hemicordylus-Cordylus clade, a distinctly western clade. The evolution of viviparity and autumn spermatogenesis in the most recent common ancestor of the Cordylinae appears to have been correlated with the onset of cooler climates during the Oligocene while the return to spring spermatogenesis appears to be have been correlated with the aridification of the western parts of southern Africa during the early Miocene.

Ancillary