Extra-Mediterranean glacial refuges in barred and common grass snakes (Natrix helvetica, N. natrix).
Scientific Reports 8, Article number: 1821 (2018). https://doi.org/10.1038/s41598-018-20218-2.
Extra-Mediterranean glacial refugia of thermophilic biota, in particular in northern latitudes, are controversial. In the present study we provide genetic evidence for extra-Mediterranean refugia in two species of grass snake. The refuge of a widely distributed western European lineage of the barred grass snake (Natrix helvetica) was most likely located in southern France, outside the classical refuges in the southern European peninsulas. One genetic lineage of the common grass snake (N. natrix), distributed in Scandinavia, Central Europe and the Balkan Peninsula, had two distinct glacial refuges. We show that one was located in the southern Balkan Peninsula. However, Central Europe and Scandinavia were not colonized from there, but from a second refuge in Central Europe. This refuge was located in between the northern ice sheet and the Alpine glaciers of the last glaciation and most likely in a permafrost region. Another co-distributed genetic lineage of N. natrix, now massively hybridizing with the aforementioned lineage, survived the last glaciation in a structured refuge in the southern Balkan Peninsula, according to the idea of ‘refugia-within-refugia’. It reached Central Europe only very recently. This study reports for the first time the glacial survival of a thermophilic egg-laying reptile species in Central Europe.
Phylogeographic Patterns in Africa and High Resolution Delineation of Genetic Clades in the Lion (Panthera leo).
Sci Rep 6, 30807 (2016). https://doi.org/10.1038/srep30807
Comparative phylogeography of African savannah mammals shows a congruent pattern in which populations in West/Central Africa are distinct from populations in East/Southern Africa. However, for the lion, all African populations are currently classified as a single subspecies (Panthera leo leo), while the only remaining population in Asia is considered to be distinct (Panthera leo persica). This distinction is disputed both by morphological and genetic data. In this study we introduce the lion as a model for African phylogeography. Analyses of mtDNA sequences reveal six supported clades and a strongly supported ancestral dichotomy with northern populations (West Africa, Central Africa, North Africa/Asia) on one branch and southern populations (North East Africa, East/Southern Africa and South West Africa) on the other. We review taxonomies and phylogenies of other large savannah mammals, illustrating that similar clades are found in other species. The described phylogeographic pattern is considered in relation to large scale environmental changes in Africa over the past 300,000 years, attributable to climate. Refugial areas, predicted by climate envelope models, further confirm the observed pattern. We support the revision of current lion taxonomy, as recognition of a northern and a southern subspecies is more parsimonious with the evolutionary history of the lion.
Gene flow between insular, coastal and interior populations of brown bears in Alaska.
Molecular Ecology 7(10): 1283-1292. https://doi.org/10.1046/j.1365-294x.1998.00440.x
The brown bears of coastal Alaska have been recently regarded as comprising from one to three distinct genetic groups. We sampled brown bears from each of the regions for which hypotheses of genetic uniqueness have been made, including the bears of the Kodiak Archipelago and the bears of Admiralty, Baranof and Chichagof (ABC) Islands in southeast Alaska. These samples were analysed with a suite of nuclear microsatellite markers. The ‘big brown bears’ of coastal Alaska were found to be part of the continuous continental distribution of brown bears, and not genetically isolated from the physically smaller ‘grizzly bears’ of the interior. By contrast, Kodiak brown bears appear to have experienced little or no genetic exchange with continental populations in recent generations. The bears of the ABC Islands, which have previously been shown to undergo little or no female‐mediated gene flow with mainland populations, were found not to be genetically isolated from mainland bears. The data from the four insular populations indicate that female and male dispersal can be reduced or eliminated by water barriers of 2–4 km and 7km in width, respectively.
Vocal Diversity and Taxonomy of Nomascus in Central Vietnam and Southern Laos.
International Journal of Primatology 31: 73–94.
Previous researchers suggested that gibbon song repertoire is genetically determined and song characteristics are useful for assessing systematic relationships. The southern white-cheeked crested gibbon is regarded as either a subspecies of Nomascus leucogenys or its own species (Nomascus siki). I studied vocal diversity among different wild populations of Nomascus in central Vietnam and southern Laos to assess their taxonomic relationships and to examine whether their vocal patterns correspond to forms previously described for Nomascus siki. I examined the songs of 7 Nomascus populations in Vietnam and Laos. I analyzed 192 song bouts from different gibbon groups including 173 phrases of 42 females and 192 phrases of 42 males. Linear discriminant analysis, classification trees, and multidimensional scaling revealed marked separation of groups in the northern and southern populations. Within the 2 geographic populations, there is little variability and the vocal characteristics exhibited no apparent cline. I conclude that the northern and southern geographic populations may represent 2 distinct taxa. I postulate that a taxonal boundary such as large rivers existing between southern Quang Binh province and northern Thua-Thien Hue province in Vietnam and northern Phou Xang He NBCA and southern Dong Phou Vieng NBCA in Laos has limited gene flow between the populations. Differing topographic features could also serve as a selective force for improved sound transmission in a highly territorial species, driving the divergence between the 2 populations.
Phylogenetic relationships of Mesoamerican spider monkeys (Ateles geoffroyi): Molecular evidence suggests the need for a revised taxonomy.
Molecular Phylogenetics and Evolution 82: 484-494.
Mesoamerican spider monkeys (Ateles geoffroyi sensu lato) are widely distributed from Mexico to northern Colombia. This group of primates includes many allopatric forms with morphologically distinct pelage color and patterning, but its taxonomy and phylogenetic history are poorly understood. We explored the genetic relationships among the different forms of Mesoamerican spider monkeys using mtDNA sequence data, and we offer a new hypothesis for the evolutionary history of the group. We collected up to ~800 bp of DNA sequence data from hypervariable region 1 (HV1) of the control region, or D-loop, of the mitochondrion for multiple putative subspecies of Ateles geoffroyi sensu lato. Both maximum likelihood and Bayesian reconstructions, using Ateles paniscus as an outgroup, showed that (1) A. fusciceps and A. geoffroyi form two different monophyletic groups and (2) currently recognized subspecies of A. geoffroyi are not monophyletic. Within A. geoffroyi, our phylogenetic analysis revealed little concordance between any of the classiﬁcations proposed for this taxon and their phylogenetic relationships, therefore a new classiﬁcation is needed for this group. Several possible clades with recent divergence times (1.7–0.8 Ma) were identiﬁed within Ateles geoffroyi sensu lato. Some previously recognized taxa were not separated by our data (e.g., A. g. vellerosus and A. g. yucatanensis), while one distinct clade had never been described as a different evolutionary unit based on pelage or geography (Ateles geoffroyi ssp. indet. from El Salvador). Based on well-supported phylogenetic relationships, our results challenge previous taxonomic arrangements for Mesoamerican spider monkeys. We suggest a revised arrangement based on our data and call for a thorough taxonomic revision of this group.
Integration of nuclear and mitochondrial gene sequences and morphology reveals unexpected diversity in the forest cobra (Naja melanoleuca) species complex in Central and West Africa (Serpentes: Elapidae)
Zootaxa 4455 (1): 068–098. http://www.mapress.com/j/zt/. ISSN1175-5334(online edition).
Cobras are among the most widely known venomous snakes, and yet their taxonomy remains incompletely understood, particularly in Africa. Here, we use a combination of mitochondrial and nuclear gene sequences and morphological data to diagnose species limits within the African forest cobra, Naja (Boulengerina) melanoleuca. Mitochondrial DNA sequences reveal deep divergences within this taxon. Congruent patterns of variation in mtDNA, nuclear genes and mor-phology support the recognition of five separate species, confirming the species status of N. subfulva and N. peroescobari, and revealing two previously unnamed West African species, which are described as new: Naja (Boulengerina) guineensis sp. nov. Broadley, Trape, Chirio, Ineich & Wüster, from the Upper Guinea forest of West Africa, and Naja (Boulengerina) savannula sp. nov. Broadley, Trape, Chirio & Wüster, a banded form from the savanna-forest mosaic of the Guinea and Sudanian savannas of West Africa. The discovery of cryptic diversity in this iconic group highlights our limited under-standing of tropical African biodiversity, hindering our ability to conserve it effectively.
A Taxonomic Revision of Boas (Serpentes: Boidae).
Zootaxa 3846 (2): 249-260.
Large molecular datasets including many species and loci have greatly improved our knowledge of snake phylogeny, particularly within the group including boas (Table 1). Recent taxonomic revisions using molecular phylogenies have clarified some of the previously contentious nomenclature of the group (Wilcox et al. 2002; Lawson et al. 2004; Burbrink 2005; Noonan & Chippindale 2006), resulting in a robust taxonomy that is mostly concordant with the phylogeny as currently known, which includes ~85% of described, extant species (Pyron et al. 2013; Reynolds et al. 2014). However, a few unresolved issues remain, related primarily to the rules of the International Code of Zoological Nomenclature (the Code hereafter) and the application of Linnaean ranks (International Commission on Zoological Nomenclature et al. 1999).
A review of the systematics of the genus Bradypodion (Sauria: Chamaeleonidae), with the description of two new genera.
Zootaxa 1363: 23–38. ISSN1175-5334 (online edition)
The taxonomic history and composition of the genus Bradypodion as construed by Klaver & Böhme (1986) and new morphological and molecular data relevant to the taxonomy of the group is reviewed. The combined evidence strongly supports a formal rearrangement of the group into three distinct genera. Bradypodion, type species Chamaeleo pumilus Daudin 1802, is retained for the southern African species. Two new genera are erected to accommodate additional well-diagnosed clades within central and east African species previously referred to Bradypodion. Species of the “fischeri complex” are assigned to Kinyongia gen. nova, whilst the endemic Mulanje chameleon is placed in the monotypic genus Nadzikambia gen. nova.
The two-horned chamaeleons of East Africa.
Zoological Journal of the Linnean Society 152 (2): 367–391, https://doi.org/10.1111/j.1096-3642.2007.00332.x
There have been numerous attempts to resolve the taxonomy of the two-horned chamaeleons of East Africa. However, the high levels of intraspecific variation and reported sympatry of morphologically distinct taxa indicate that their current classification is unsatisfactory. Tissue samples were collected from specimens from most mountain massifs (excluding the Nguu) where two-horned chamaeleons are known to occur and were used to sequence partial 12S and 16S rRNA, as well as ND2 mtDNA genes. These specimens and further museum material were used to review morphological variation and to define discriminating characters for each taxon. Phylogenetic analyses of gene sequences show clear genetic divergence between allopatric populations, although two lineages occur in sympatry in the East Usambara Mountains, and is supported by divergent morphology. In light of these results a formal revision of the taxonomy of all East African two-horned chamaeleons is proposed and seven species are recognized (Kinyongia boehmei, K. fischeri, K. matschiei, K. multituberculata, K. tavetana, K. uluguruensis and K. vosseleri). These taxa form a monophyletic group except for K. uluguruensis, which seems to be more closely related to one-horned species. Most of these taxa have been previously described and subsequently reduced to synonyms. Two other previously described two-horned taxa are not recognized as valid: Chamaeleo tornieri is considered species inquiriendae, and C. fischeri werneri is placed in synonymy with K. multituberculata. A dichotomous key is provided for the identification of these taxa and some aspects of their conservation, ecology and evolutionary origins are also discussed.
A review of the Malagasy Pachypanchax (Teleostei: Cyprinodontiformes, Aplocheilidae), with descriptions of four new species.
Zootaxa 1366: 1–44. ISSN 1175-5334 (online edition)
The history of the genus Pachypanchax Myers, 1933 in the literature is reviewed and the utility of
the diagnostic characters proposed by various authors is evaluated. On the basis of five
synapomorphies, four skeletal and one squamational, six of the seven presently known Malagasy
aplocheilids are found to be unambiguously referable to the genus Pachypanchax. The seventh,
Poecilia nuchimaculata Guichenot 1866, known only from the unique type specimen, displays
several peculiar skeletal and squamational features. Pending the acquisition of additional material,
it is tentatively assigned to the genus. Of the six species treated here, Pachypanchax omalonotus
(Duméril, 1861) and P. sakaramyi (Holly, 1828) are redescribed from recently collected topotypical
material; and the following four are described as new: P. varatraza., P. patriciae, P. sparksorum,
and P. arnoulti. Data on life colors, distribution, natural history and conservation status on all six
Malagasy Pachypanchax species are presented.