Search Results

No Access

D. James Harris and Miguel Carretero

No Access

Mathieu Denoël and D. James Harris

No Access

Raquel Vaconcelos, D. James Harris and Miguel Carretero

Abstract

The evolutionary relationships of amphisbaenians of the genus Blanus have long been controversial. Presently two species are recognized for Morocco — Blanus tingitanus and B. mettetali and one for Iberia — B. cinereus. Using mitochondrial and nuclear DNA sequences, 25 samples from Portugal, Spain and Morocco were analysed. Both markers indicate the existence of three well-separated clades: one for the Northern Moroccan samples, corresponding to B. tingitanus and two to the B. cinereus samples. One sample from Taza, Morocco, was identical to specimens from one of the Iberian forms. These results point to the necessity of a systematic revision. These new groups reinforce the need for geographically broader sampling accompanied by morphological studies to fully determine the phylogenetic history of this species complex.

No Access

Fernando Sequeira, Nuno Ferrand and D. James Harris

Abstract

The potential of the seventh intron of the β-subunit of the fibrinogen gene (β-fibint 7) for phylogenetic analysis within the Salamandridae family was explored, comparing the topologies of trees based on this marker to those based on mitochondrial 12S rRNA gene previously published. Using primers designed specifically for amphibians, we amplified 25 sequences of β-fibint 7 corresponding to 15 species of salamandrids and one plethodontid species. There was considerable length variation among the β-fibint 7 sequences examined, ranging from 1123 bp in S. atra to 400 bp in P. waltl. Many aspects of the phylogenetic relationships estimated by the two independent loci were congruent and corroborate current taxonomic hypothesis. Although the number of taxa analysed is small, the data obtained in this work suggested that β-fibint 7 is a useful marker for assessing phylogenetic relationships within the Salamandridae family, and is probably appropriate for phylogenetic studies among closely related salamanders that have diverged over the last 20 Myr.

No Access

D. James Harris and Paulo Sá-Sousa

Abstract

Podarcis carbonelli is considered a full species on the basis of its morphological and genetic divergence from P. bocagei and P. hispanica. Podarcis carbonelli differs from P. bocagei in all twelve biometric variables compared and also in chromatic patterns. Podarcis carbonelli diverges from P.bocagei by more than 13% between cytochrome b sequences (mitochondrial DNA), a value typically reported between congeneric reptile species. Biogeographical criteria also support this hypothesis, as both lizard forms have different distribution ranges with a limited parapatric zone of contact without morphological intermediates.

No Access

António Brehm, José Jesus and D. James Harris

Abstract

Thirteen specimens of Tarentola from the Cape Verde islands were sequenced for 695 base pairs of 12S rRNA and cytochrome b mitochondrial genes, and analysed with published sequences. Our results support many of the relationships previously proposed. We report the presence of Tarentola gigas Bocage, 1875 on São Nicolau and Tarentola caboverdiana nicolauensis Schleich, 1984 on São Vicente. This increases the number of genetically distinct forms on these islands; hence community structure appears to be more complex than previously understood. We also sequenced seven individuals for 375 base pairs of the nuclear gene, C-mos. Two sites were variable, much less than expected given the high levels of differentiation based on mitochondrial DNA sequences.

No Access

José Jesus, D. James Harris and António Brehm

Abstract

Relationships of Mabuya lizards from the islands of the Gulf of Guinea where estimated using partial 12S rRNA, 16S rRNA and cytochrome b mitochondrial gene sequences. Mabuya maculilabris from São Tomé and Principe are discreet monophyletic units, highly divergent from each other and from mainland populations, indicating M. maculilabris may be a species complex. Mabuya affinis from Principe is similarly distinct from mainland populations of this species. The relationships of Mabuya ozorii from Annobon are unclear, but the three species in the Gulf of Guinea islands are not closely related, indicating multiple independent colonization events. The recent proposal to partition Mabuya into four genera is premature, since at least five distinct genetic lineages can be identified.

No Access

Sara Rocha, D. James Harris and Miguel Carretero

Abstract

Western Indian Ocean islands (excluding Madagascar) are inhabited by at least five species of the lizard genus Mabuya, for which diversity and inter-island phylogenetic relationships are still unclear, particularly concerning island populations of M. maculilabris, M. comorensis and M. striata. With a comprehensive sampling across the Comoros archipelago and the islands of Zanzibar and Pemba (Tanzania) we use molecular data and previously published sequences of these species to describe genetic variation across their insular range and explore the possible distinction of insular populations of the different species, contributing to the clarification of their status and knowledge of their colonization patterns. We describe patterns of cryptic diversity within M. comorensis, revealing a West to East colonization of the Comoros archipelago and clarify the status of Malagasy populations of this species. Cryptic variation is also observed within M. maculilabris and M. striata, and the status of several continental and island populations discussed. M. sechellensis is shown to be paraphyletic relative to M. wrightii. Available data for all Afro-Malagasy Mabuya reveals additional possible instances of paraphyly within some species but does not allow for further resolution of basal relationships within this group, pointing to rapid and simultaneous divergences within this group and the need for multiple independent markers to recover the history of this group.

No Access

José Brito, Raquel Vaconcelos and D. James Harris

Abstract

African spiny-tailed lizards (Uromastyx) are large, herbivorous lizards extensively traded locally for food and internationally as pets. Several species have recently been described, although some remain controversial. To determine relationships within North African forms, twenty individuals were analysed for over 1000 bases of mitochondrial DNA sequences. Phylogenetic analyses indicate four deeply divergent lineages that correspond to sampling areas, but not to current species designations. These results indicate that present taxonomy does not reflect the evolutionary history of these species.

No Access

D. James Harris, Nuno Ferrand, Eduardo Crespo and Raquel Godinho

Abstract

Partial DNA sequences from three mitochondrial (cytochrome b, 12S rRNA and 16S rRNA) and two nuclear (β-fibrinogen intron 7 and C-mos) genes were used to estimate the phylogenetic relationships among all eight extant species of green lizards, Lacerta sensu stricto, and many currently recognized subspecies. All eight species form a monophyletic group. L. agilis, L. schreiberi and L. strigata are genetically well differentiated species. L. trilineata and L. pamphylica are not monophyletic units based on analyses of the β-fibrinogen intron 7. Lacerta media is closely related to some Lacerta trilineata. L. bilineata and L. viridis are closely related, and recognition of L. bilineata as a distinct species makes L. viridis paraphyletic also. For both L. bilineata and L. viridis, some subspecies appear to remain in their southern glacial refugia, while a single genetic entity shows successfully postglacial expansion. The topology derived from C-mos variation is concordant with that derived from mtDNA, with substitutions occurring at a similar rate to that of transversions in the rRNA genes. Although C-mos is typically used at deeper taxonomic levels it is also phylogenetically informative within green lizards. β-fibrinogen intron 7, typically used for assessing phylogenetic relationships among bird species, is a useful phylogenetic marker for reptiles also, showing considerable variation between species. There is not complete concordance between estimates of relationships derived from the mtDNA and nuclear markers, probably because rapid diversification led to incomplete lineage sorting in the green lizards. Introgression could also be occuring between some species.