Abstract:Aim Geckos (Reptilia: Squamata), due to their great age and global distribution, are excellent candidates to test hypotheses of Gondwanan vicariance against post‐Gondwanan dispersal. Our aims are: to generate a phylogeny of the sphaerodactyl geckos and their closest relatives; evaluate previous phylogenetic hypotheses of the sphaerodactyl geckos with regard to the other major gecko lineages; and to use divergence date estimates to inform a biogeographical scenario regarding Gondwanan relationships and assess … Show more
“…Gecko genera with similar species richness to Lepidodactylus (e.g. Gehyra) are significantly older than Mid-Cenozoic in age, and the divergence between Gekko and Lepidodactylus has been estimated to have occurred near the K/T boundary, 65 Ma [18,19], hinting at earlier ages of origin for Luperosaurus as well. We performed phylogenetic and timing analyses on a dataset, including Asian flap-bearing geckos, as well as most other Southeast Asian and Pacific gekkonid genera, to both investigate evolutionary relationships among the arboreal Asian gecko genera and evaluate the tenability of a correlation between dipterocarp forest development and the evolution of gliding morphologies.…”
).Gliding morphologies occur in diverse vertebrate lineages in Southeast Asian rainforests, including three gecko genera, plus frogs, snakes, agamid lizards and squirrels. It has been hypothesized that repeated evolution of gliding is related to the dominance of Asian rainforest tree floras by dipterocarps. For dipterocarps to have influenced the evolution of gliding in Southeast Asian vertebrates, gliding lineages must have Eocene or later origins. However, divergence times are not known for most lineages. To investigate the temporal pattern of Asian gliding vertebrate evolution, we performed phylogenetic and molecular clock analyses. New sequence data for geckos incorporate exemplars of each gliding genus (Cosymbotus, Luperosaurus and Ptychozoon), whereas analyses of other vertebrate lineages use existing sequence data. Stem ages of most gliding vertebrates, including all geckos, cluster in the time period when dipterocarps came to dominate Asian tropical forests. These results demonstrate that a gliding/dipterocarp correlation is temporally viable, and caution against the assumption of early origins for apomorphic taxa.
“…Gecko genera with similar species richness to Lepidodactylus (e.g. Gehyra) are significantly older than Mid-Cenozoic in age, and the divergence between Gekko and Lepidodactylus has been estimated to have occurred near the K/T boundary, 65 Ma [18,19], hinting at earlier ages of origin for Luperosaurus as well. We performed phylogenetic and timing analyses on a dataset, including Asian flap-bearing geckos, as well as most other Southeast Asian and Pacific gekkonid genera, to both investigate evolutionary relationships among the arboreal Asian gecko genera and evaluate the tenability of a correlation between dipterocarp forest development and the evolution of gliding morphologies.…”
).Gliding morphologies occur in diverse vertebrate lineages in Southeast Asian rainforests, including three gecko genera, plus frogs, snakes, agamid lizards and squirrels. It has been hypothesized that repeated evolution of gliding is related to the dominance of Asian rainforest tree floras by dipterocarps. For dipterocarps to have influenced the evolution of gliding in Southeast Asian vertebrates, gliding lineages must have Eocene or later origins. However, divergence times are not known for most lineages. To investigate the temporal pattern of Asian gliding vertebrate evolution, we performed phylogenetic and molecular clock analyses. New sequence data for geckos incorporate exemplars of each gliding genus (Cosymbotus, Luperosaurus and Ptychozoon), whereas analyses of other vertebrate lineages use existing sequence data. Stem ages of most gliding vertebrates, including all geckos, cluster in the time period when dipterocarps came to dominate Asian tropical forests. These results demonstrate that a gliding/dipterocarp correlation is temporally viable, and caution against the assumption of early origins for apomorphic taxa.
“…Therefore, the invasion of a tropically adapted, ancestral Gehyra from the Melanesian region at this time is plausible and supported by our ancestral state reconstruction analysis. In contrast with the other Australian Gekkotan lineages which have a Gondwanan origin, the divergence between Australian and Melanesian Gehyra is more recent (Gamble et al, 2008b;Oliver and Sanders, 2009) as is consequently the diversification within Australian Gehyra.…”
Species tree methods have provided improvements for estimating species relationships and the timing of diversification in recent radiations by allowing for gene tree discordance. Although gene tree discordance is often observed, most discordance is attributed to incomplete lineage sorting rather than other biological phenomena, and the causes of discordance are rarely investigated. We use species trees from multi-locus data to estimate the species relationships, evolutionary history and timing of diversification among Australian Gehyra-a group renowned for taxonomic uncertainty and showing a large degree of gene tree discordance. We find support for a recent Asian origin and two major clades: a tropically adapted clade and an arid adapted clade, with some exceptions, but no support for allopatric speciation driven by chromosomal rearrangement in the group. Bayesian concordance analysis revealed high gene tree discordance and comparisons of Robinson-Foulds distances showed that discordance between gene trees was significantly higher than that generated by topological uncertainty within each gene. Analysis of gene tree discordance and incomplete taxon sampling revealed that gene tree discordance was high whether terminal taxon or gene sampling was maximized, indicating discordance is due to biological processes, which may be important in contributing to gene tree discordance in many recently diversified organisms.
“…Distribution patterns are corroborated as 'Gondwanan' if they are considered old enough (e.g. Gamble et al, 2008), and rejected as 'Gondwanan' if they are not (Barker et al, 2007).…”
Biogeography needs a standard, coherent nomenclature. Currently, in biogeography, the same name is used for different areas of biological endemism, and one area of endemism is known by more than one name, which leads to conflict and confusion. The name ‘Mediterranean’, for example, may mean different things to different people – all or part of the sea, or the land in and around it. This results in ambiguity concerning the meaning of names and, more importantly, may lead to conflicts between inferences based on different aspects of a given name. We propose the International Code of Area Nomenclature (ICAN), a naming system that can be used to classify newly coined or existing names based on a standard. When fully implemented, the ICAN will improve communication among biogeographers, systematists, ecologists and conservation biologists.
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