Free Access
Genet. Sel. Evol.
Volume 33, Number 6, November-December 2001
Page(s) 671 - 685
DOI: 10.1051/gse:2001103

Genet. Sel. Evol. 33 (2001) 671-685

Lack of congruence between morphometric evolution and genetic differentiation suggests a recent dispersal and local habitat adaptation of the Madeiran lizard Lacerta dugesii

António Brehma, Mahnaz Khademb, José Jesusa, Paula Andradeb and Luis Vicentec

a  Centre of Biological and Geological Sciences, Campus of Penteada, 9000 Funchal, Portugal
b  Department of Biology, University of Madeira, 9000 Funchal, Portugal
c  Centre of Environmental Biology, Departments of Zoology and Anthropology, Science Faculty of Lisbon, University of Lisbon, C2 Campo Grande, 1700 Lisbon, Portugal

(Received 22 March 2000; accepted 6 July 2001)

Genetic differentiation among nine populations of the endemic lizard Lacerta dugesii Milne-Edwards 1829 (Lacertidae) from four groups of islands constituting the Archipelago of Madeira, was investigated by protein electrophoresis at 23 enzyme loci. Among twenty polymorphic loci, the total genetic diversity was due primarily to intra-population variation. The allele and genotypic frequencies among populations showed some heterogeneity, allowing the species to present a structuring pattern compatible with their geographical clustering. Some evidence suggests that selection acting on some loci in different ecological conditions may be responsible for the clustering of the populations studied. There was no apparent isolation effect expected under an "island" model of population divergence, and no correlation was found between genetic and geographic distances among populations. Morphological variation of the proposed three L. dugesii subspecies is not congruent with the allozyme analysis. This most probably suggests a rapid colonization of the islands followed by a strong effect of selection operating over the morphological characters used to define the subspecies.

Key words: Lacerta dugesii / allozymes / morphology / geographical population structure

Correspondence and reprints: António Brehm

© INRA, EDP Sciences 2001