Complex patterns of morphological and mtDNA variation in Lacerta perspicillata (Reptilia; Lacertidae)

Abstract

Lacerta perspicillata is a north-west African lacertid lizard that shows considerable intraspecific variation, with three subspecies described on the basis of colour pattern and body size. Recent observations of a population con- taining two morphological forms and more than one deep genetic lineage, as well as an apparent lack of concordance between forms and genetic lineages, suggest that the complexity is greater than previously thought. To analyse and quantify this variation, we studied the variability within this species at two levels: (1) external morphology (multivariate analysis of scalation, body dimensions, and colour pattern) and (2) mtDNA (sequencing and single- strand confirmation polymorphism analysis). Fifty-two individuals were studied at Taza, northern Morocco. Two morphological groupings (ostensibly representing two previously described subspecies) and two deep mtDNA lin- eages were detected at this site, with complete correspondence between the two. This, together with an apparent lack of hybrids, would normally support respective full species recognition. However, analysis of 98 individuals from other populations demonstrated that the situation is highly complex with the same genetic lineages having reversed mor- photypes in other areas, making such a designation difficult. Across the other studied populations, we found no sup- port for any of the currently recognized subspecies. The lack of congruence between mtDNA lineages and morphometric patterns (in some cases) and the morphological similarity among lizards from different lineages sug- gest ecophenotypic convergence or multiple introgressive hybridization. The study highlights the tremendous com- plexity that may exist within a taxon and the inadequacy of older alpha-taxonomy based designations in describing it. © 2007 The Linnean Society of London, Biological Journal of the Linnean Society , 2007, 90 , 479-490. ADDITIONAL KEYWORDS: Balearic Islands - genetic variation - lizard - morphology - North Africa.