Out of southern Africa: Origins and cryptic speciation in Chamaeleo, the most widespread chameleon genus

An island in a sea of sand: a first checklist of the herpetofauna of the Serra da Neve inselberg, southwestern Angola

The Serra da Neve inselberg in Namibe Province, southwestern Angola is the second highest peak of Angola with an elevation of 2489 m. It remains one of the least explored regions in the country, despite several endemic species having been recently described from this inselberg. Here we provide an inventory of the amphibian and reptile species ocurring in Serra da Neve and compare its fauna with that of the surrounding habitats at lower elevations. We also examine the phylogenetic affinities of the inselberg taxa. A total of 59 herpetological taxa were recorded for the Serra da Neve inselberg and its immediate surroundings. These include 11 species of amphibians, belonging to nine genera and seven different families, and 48 species of reptiles, belonging to 32 genera and 12 families. Of these, one amphibian and seven reptiles from seven different genera are strictly endemic, making the inselberg the richest region in southwestern Africa with respect to strict endemics, with one endemic reptile taxa per 127 km2. Not surprisingly, most of the recorded taxa belong to clades that are endemic, or at least strongly associated, with southern Africa, but two are representatives of central African clades, and another two are more closely related to eastern African highland taxa. We also provide comments on the threats to the conservation of this endemic-rich inselberg.

The efficacy of single mitochondrial genes at reconciling the complete mitogenome phylogeny-a case study on dwarf chameleons

Although genome-scale data generation is becoming more tractable for phylogenetics, there are large quantities of single gene fragment data in public repositories and such data are still being generated. We therefore investigated whether single mitochondrial genes are suitable proxies for phylogenetic reconstruction as compared to the application of full mitogenomes. With near complete taxon sampling for the southern African dwarf chameleons (Bradypodion), we estimated and compared phylogenies for the complete mitogenome with topologies generated from individual mitochondrial genes and various combinations of these genes. Our results show that the topologies produced by single genes (ND2, ND4, ND5, COI, and COIII) were analogous to the complete mitogenome, suggesting that these genes may be reliable markers for generating mitochondrial phylogenies in lieu of generating entire mitogenomes. In contrast, the short fragment of 16S commonly used in herpetological systematics, produced a topology quite dissimilar to the complete mitogenome and its concatenation with ND2 weakened the resolution of ND2. We therefore recommend the avoidance of this 16S fragment in future phylogenetic work.

Multiple contact zones and karyotypic evolution in a neotropical frog species complex

Previous studies of DNA sequence and karyotypic data have revealed high genetic diversity in the Physalaemus cuvieri - Physalaemus ephippifer species complex-a group of small leptodactylid frogs in South America. To date, seven major genetic lineages have been recognized in this group, with species delimitation tests supporting four to seven of them as valid species. Among these, only P. ephippifer shows heteromorphic sex chromosomes, but the implications of cytogenetic divergence for the evolution of this group are unknown. We analyzed karyotypic, mitochondrial DNA, and 3RAD genomic data to characterize a putative contact zone between P. ephippifer and P. cuvieri Lineage 1, finding evidence for admixture and karyotypic evolution. We also describe preliminary evidence for admixture between two other members of this species complex-Lineage 1 and Lineage 3 of P. cuvieri. Our study sheds new light on evolutionary relationships in the P. cuvieri - P. ephippifer species complex, suggesting an important role of karyotypic divergence in its evolutionary history and underscoring the importance of hybridization as a mechanism of sex chromosome evolution in amphibians.