Quantifying the incredible diversity of life is a foundational ambition of biological research. Concomitant with this goal, biologists have sought ways of measuring and characterizing complex anatomical structures, for the purposes of deciphering patterns of variation in phenotypic traits, and its covariation with other variables. The field of geometric morphometrics (GM) provides a set of tools for accomplishing these tasks Bookstein, 1991;Rohlf & Marcus, 1993). Many of these tools utilize sets of landmark coordinates-from anatomical points, curves and surfaces-as the basis of shape quantification, and from which patterns of shape variation are determined. Over the past several decades, the analytical theory of geometric morphometrics has continued to develop, and so too has the need for improved computational tools to implement these approaches. While standalone GM software continues to be utilized (e.g. TPS-series:

BackgroundPleistocene climatic oscillations have played a major role in structuring present-day biodiversity. The southern Mediterranean peninsulas have long been recognized as major glacial refugia, from where Northern Europe was post-glacially colonized. However, recent studies have unravelled numerous additional refugia also in northern regions. We investigated the phylogeographic pattern of the widespread Western Palaearctic lizard Podarcis muralis, using a range-wide multilocus approach, to evaluate whether it is concordant with a recent expansion from southern glacial refugia or alternatively from a combination of Mediterranean and northern refugia.ResultsWe analyzed DNA sequences of two mitochondrial (cytb and nd4) and three nuclear (acm4, mc1r, and pdc) gene fragments in individuals from 52 localities across the species range, using phylogenetic and phylogeographic methods. The complex phylogeographic pattern observed, with 23 reciprocally monophyletic allo- parapatric lineages having a Pleistocene divergence, suggests a scenario of long-term isolation in multiple ice-age refugia across the species distribution range. Multiple lineages were identified within the three Mediterranean peninsulas – Iberia, Italy and the Balkans - where the highest genetic diversity was observed. Such an unprecedented phylogeographic pattern - here called “refugia within all refugia” – compasses the classical scenario of multiple southern refugia. However, unlike the southern refugia model, various distinct lineages were also found in northern regions, suggesting that additional refugia in France, Northern Italy, Eastern Alps and Central Balkans allowed the long-term persistence of this species throughout Pleistocene glaciations.ConclusionsThe phylogeography of Podarcis muralis provides a paradigm of temperate species survival in Mediterranean and extra-Mediterranean glacial refugia. Such refugia acted as independent biogeographic compartments for the long-term persistence of this species, for the differentiation of its genetic lineages, and for the short-distance post-glacial re-colonization of neighbouring areas. This finding echoes previous findings from recent phylogeographic studies on species from temperate ecoregions, thus suggesting the need for a reappraisal of the role of northern refugia for glacial persistence and post-glacial assembly of Holarctic biota.

Evolutionary inference based on molecular phylogenetic methods has profoundly modified the way that we understand biological diversity, unravelling a higher evolutionary diversity than previously considered. An exemplary case of this is the group of Iberian and North African Podarcis wall lizards. More investigated than any other reptile group in Europe, the Podarcis hispanica species complex comprises unexpectedly high levels of phylogenetic diversity and illustrates how the discovery of further cryptic diversity may entangle evolutionary inference. In the present study, we report on the discovery of two new mitochondrial lineages in this species complex, reassess the phylogeny of the group, infer the age of major phylogenetic splits, and provide a detailed description of the geographical distributions of all known mitochondrial DNA lineages. Our data show that the differentiation of major lineages is older than previously considered, in most cases predating the Messinian salinity crisis. The new lineages discovered and their position in the phylogeny of the group profoundly modify previous biogeographical scenarios, clearly showing that the area today corresponding to the south-eastern corner of the Iberian Peninsula is a very important centre of diversification. The dating obtained for the differentiation of the lineages currently inhabiting this area coincides with the complex geological events that took place during the Miocene/Pleistocene transition, supporting the idea that both land movements and dramatic climatic oscillations during that period could be involved. Finally, the discovery of these new lineages, together with the observed distribution patterns, not only further augments the uncertainty associated to our understanding of the evolutionary history of this group of lizards, but also points to new areas of interest for future investigation.

Podarcis bocagei and P. carbonelli are two closely related lacertid species, very similar morphologically and ecologically. We investigated sexual dimorphism patterns presented by both species in allopatry and in sympatry. Sexual size and shape dimorphism patterns were analyzed using both multivariate and geometric morphometric techniques. Multivariate morphometrics revealed a marked sexual dimorphism in both species-males being larger with more robust habitus and females presenting a longer trunk. General patterns of sexual size dimorphism are not modified in sympatry, although there is evidence for some morphological change in male head size. The application of geometric morphometrics offered a more detailed image of head shape and revealed that males present a more developed tympanic area than do females, while females have a more rounded head. Differences in the degree of sexual shape dimorphism were detected in sympatry, but no consistent patterns were observed. From the results of the study, and based on previous knowledge on the populations studied, we conclude that the morphological differences observed are probably not caused by exploitative competition between the species, but rather appear attributable to the modification of the relative influence of sexual and natural selection on both sexes. J. Morphol. 268:152-165, 2007 2007 Wiley-Liss, Inc.