Biogeography
The Phelsuma lineata-group unraffled?
14/07/13 07:57
A recently published article in the “Organisms Diversity & Evolution” unravels the complicated Phelsuma lineata-group by mtDNA sampling and analysis.
Day geckos of the Phelsuma lineata-group are widespread in Madagascar and have been historically split into numerous species and subspecies based almost exclusively on differences in coloration and body size. We apply phylogenetic and phylogeographic methods to examine the biogeography and taxonomy of these lizards, including explicit tests of various biogeographic predictions and based on a molecular data set covering much of the distribution ranges of all species and subspecies of P. lineata, P. dorsivittata, P. comorensis, P. hoeschi, P. kely, and P. pusilla in Madagascar (and the Comoros archipelago for P. comorensis).
Sequences of the mitochondrial 16S rRNA and the nuclear RAG-1 gene fragment were determined from 376 samples, and a multigene mtDNA phylogeny of the species group was constructed for the main phylogroups identified in the 16S haplotype network. We used the 16S sequences to estimate the geographic location of the ancestor of each major mtDNA clade and to infer their demographic history using a variety of statistical tools. Our phylogeny separates the taxa analyzed into two well-supported major subclades mainly occurring in the north respectively east of the island.
Mismatch distribution of samples together with rejection of neutrality, the results of Bayesian Skyline Plots analysis, and a star-like network suggests a recent demographic expansion for the P. l. lineata lineage into the eastern lowlands, while the highland (P. l. elanthana) and northern clades (P. dorsivittata and P. l. punctulata) show signatures of rather stable populations.
Phelsuma dorsivittata from the Ampasindava peninsula © Emmanuel Van Heygen
A major genetic discontinuity observed coincided with a northern lowland stretch that separates mid-altitude rainforests in the north from those in the center and south. Our analysis points to numerous unsolved taxonomic problems in this group of geckos, especially in the small-sized taxa (P. hoeschi, P. kely, P. pusilla), and provides a basis for a future comprehensive taxonomic revision, which will require integrative analysis of molecular, morphological and chromatic data as well as careful examination of type specimens.
Reference
Gehring, P. S., F. Glaw, M. Gehara, F. M. Ratsoavina & M. Vences (2013): Northern origin and diversification in central lowlands? - Complex phylogeography and taxonomy of widespread day geckos (Phelsuma) from Madagascar. – Organisms, Diversity and Evolution, published online.
Day geckos of the Phelsuma lineata-group are widespread in Madagascar and have been historically split into numerous species and subspecies based almost exclusively on differences in coloration and body size. We apply phylogenetic and phylogeographic methods to examine the biogeography and taxonomy of these lizards, including explicit tests of various biogeographic predictions and based on a molecular data set covering much of the distribution ranges of all species and subspecies of P. lineata, P. dorsivittata, P. comorensis, P. hoeschi, P. kely, and P. pusilla in Madagascar (and the Comoros archipelago for P. comorensis).
Sequences of the mitochondrial 16S rRNA and the nuclear RAG-1 gene fragment were determined from 376 samples, and a multigene mtDNA phylogeny of the species group was constructed for the main phylogroups identified in the 16S haplotype network. We used the 16S sequences to estimate the geographic location of the ancestor of each major mtDNA clade and to infer their demographic history using a variety of statistical tools. Our phylogeny separates the taxa analyzed into two well-supported major subclades mainly occurring in the north respectively east of the island.
Mismatch distribution of samples together with rejection of neutrality, the results of Bayesian Skyline Plots analysis, and a star-like network suggests a recent demographic expansion for the P. l. lineata lineage into the eastern lowlands, while the highland (P. l. elanthana) and northern clades (P. dorsivittata and P. l. punctulata) show signatures of rather stable populations.
Phelsuma dorsivittata from the Ampasindava peninsula © Emmanuel Van Heygen
A major genetic discontinuity observed coincided with a northern lowland stretch that separates mid-altitude rainforests in the north from those in the center and south. Our analysis points to numerous unsolved taxonomic problems in this group of geckos, especially in the small-sized taxa (P. hoeschi, P. kely, P. pusilla), and provides a basis for a future comprehensive taxonomic revision, which will require integrative analysis of molecular, morphological and chromatic data as well as careful examination of type specimens.
Reference
Gehring, P. S., F. Glaw, M. Gehara, F. M. Ratsoavina & M. Vences (2013): Northern origin and diversification in central lowlands? - Complex phylogeography and taxonomy of widespread day geckos (Phelsuma) from Madagascar. – Organisms, Diversity and Evolution, published online.
The genus Phelsuma on the Ampasindava peninsula, Madagascar
20/08/04 13:14
Van Heygen, E. 2004. The genus Phelsuma Gray, 1825 on the Ampasindava peninsula, Madagascar. Phelsuma 12: 99—117
Abstract.— Several key locations were researched on the Ampasindava peninsula, north-western Madagascar in June 2004. These locations were chosen for their probability of having remaining patches of primary vegetation. Next to the unexpected records of Phelsuma quadriocellata, a species normally occurring on Madagascar’s eastern coast, a new species, P. vanheygeni (Lerner 2004) was discovered. Known distribution ranges for other species were extended, however there presence on the peninsula was expected. These species are; P. abbotti, P. dubia, P. laticauda, P. madagascariensis, P. klemmeri and P. seippi. The first detailed report on the habitat of P. klemmeri is made since the description of the species by Seipp in 1991.
Keywords.— Phelsuma, Ampasindava peninsula, Madagascar
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Abstract.— Several key locations were researched on the Ampasindava peninsula, north-western Madagascar in June 2004. These locations were chosen for their probability of having remaining patches of primary vegetation. Next to the unexpected records of Phelsuma quadriocellata, a species normally occurring on Madagascar’s eastern coast, a new species, P. vanheygeni (Lerner 2004) was discovered. Known distribution ranges for other species were extended, however there presence on the peninsula was expected. These species are; P. abbotti, P. dubia, P. laticauda, P. madagascariensis, P. klemmeri and P. seippi. The first detailed report on the habitat of P. klemmeri is made since the description of the species by Seipp in 1991.
Keywords.— Phelsuma, Ampasindava peninsula, Madagascar
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Dispersal of the Genus Phelsuma in the Mascarenes
01/07/03 13:47
All Mascarene species are closely related, indicating they must have had a common ancestor. On the other hand are the islands to young to have generated such a diverse group, with Phelsuma gigas on one end and Phelsuma inexpectata on the other. Most likely the source pool of this group was situated away from the fast speciation process and taxon cycle on Madagascar. 20.000 Years ago, Saya de Malha and Nazareth (incl. Cargados Carajos) formed large islands about 700 km north-east of Madagascar. The first of these islands (Saya de Malha) was formed about 35 Ma and was probably never submerged until the last ice age 18.000 years ago. Read More...
The role of the ice ages in the dispersal of the genus Phelsuma.
01/07/03 13:39
Gondwana began to break up during Late Triassic to Early Jurassic time. Major mantle plumes such as the Karoo-Ferrar Plume that first split Gondwana at about 182 Ma, the Paraná-Etendeka plume at 132 Ma that split South America and Africa, the Marion plume at 88 Ma that split Madagascar and India and finally the Reunion hotspot that split the Mascarene Plateau from India at 64 Ma. Read More...
The Dodo's stepping stones the same as Phelsuma?
01/07/03 12:00
The dodo was a flightless bird native to the island of Mauritius in the Indian Ocean. DNA from the extinct bird has revealed its place in the pigeon family tree, and suggests how it came to end up on its home, and graveyard, the island of Mauritius.
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