Welcome to the homepage of Miguel Vences
The flash menu above will allow you to explore various aspects of my current and past research.
If your browser does not display the flash menu correctly use the following links and those at the bottom of the pages to browse through my scientific interests, CV, publications, and to continue to the homepage of the Vences lab at the Technical University of Braunschweig.
See slide show of amphibian and reptile diversity in Madagascar
Research highlights:
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Ancient rafters
Lemurs and tenrecs, miniature chameleons and giant snakes, poison frogs and colorful cichlid fishes: Madagascar's animal assemblages are unique, diverse and highly threatened by extinction. But how did these remarkable animals arrive on Madagascar? For long time, this question was unsolved and had been considered to be one of the largest biogeographic mysteries. Madagascar is isolated since the Cretaceous period from all other continents. Fossils from the end of that period, around 70 million years old, suggest a very different assemblage of ancient animals without any obvious relationships to Madgascar's current fauna: dinosaurs and marsupial mammals, lungfishes and gars, vegetarian crocodiles and giant toads walked on the island in that period. Two articles published in PNAS shed light on the origins of Madagascar's extant vertebrates. Using a comprehensive timetree of Madagascar's endemic vertebrate clades we assessed that the ancestors of most of these animals arrived around the KT-boundary, 70-60 million years ago, on Madagascar's shores, and that the key for their current species richness was the subsequent colonization of rainforest. In parallel, Karen Samonds and collaborators reached similar conclusion based on an analysis of the arrival patterns of these vertebrate clade ancestors in Madagascar which supported hypotheses drawn from paleogeographic and paleoclimatic reconstructions.
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Liliputian lizards
The fastest, the largest, the heaviest or the smallest: 
humans are interested in the extremes of nature, as shown by many entries in the Guiness book of records. However, determining such records is always subjective since it depends on which measurement is taken into account. In amniotes, if the measure is total length, then Brookesia micra, a new species described from Madagascar along with three other miniaturized leaf chameleons, qualifies indeed as the smallest species of all, although its snout-vent length is admittedly not below that of two miniaturized Caribbean Sphaerodactylus geckos. Independent from such discussions, the truely interesting fact about these tiny chameleons is their high amount of genetic differentiation, suggesting very old ages since divergence, and their extremely microendemic occurrence in northern Madagascar. Brookesia micra is so far only known from forest fragments on Nosy Hara islet, with a probable area of occupancy below 50 ha. How these lizards have persisted in such small ranges for millions of years is a mistery.
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Frog is in the Air
Frogs mostly communicate acoustically but the use of peptide pheromones in the water or through direct contact is known from numerous species of anurans as it is from salamanders. Many frogs have sexually dimorphic macrogland structures of largely unknown function that have been hypothesized to be involved in chemical communiation.
In a project led by Stefan Schulz and Dennis Poth we demonstrated that the femoral glands typical for the males of some Malagasys frogs produce compounds that are partly known to act as volatile airborne pheromones in insects, and we experimentally found some of these compounds to probably alter the behavior of the frogs. Pheromone composition was species-specific and these chemical cues could serve as important short-distance recognition mechanism in species-rich tropical amphibian communities. We hypothesize that divergence in chemical signals might also be relevant in the speciation process in these frogs and merits further investigation.
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Speciation in Little
Which factors influence species diversification? On a basis of a newly assembled molecular phylogeny of the Malagasy frog family Mantellidae, with a near-complete taxon sampling of 257 nominal and candidate species, a study led by Katharina Wollenberg analyzed the evolution of various traits of these frogs. We found a strong correlationbetween body size and range sze, confirming that small frogs have smaller distribution ranges, and this correlation was also significant after phylogenetic correction. Microendemic and small-sized sister species have more proximate ranges and climatically more similar niches than widely distributed or larger species, and young pairs of sister species were distrimuted in closer spatial proximity than older pairs of sister species. This rejects a predominant role of peripatric speciation in these frogs and suggests the possibility of adaptive species formation.
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Integrative Taxonomy
Our understanding about what species are has significantly progressed in the last decade: most biologists will today agree that species are separately evolving lineages at the population or metapopulation level, but it remains controversial how we can recognize that two lineages indeed are on independent evolutionary trajectories, and when such entities should be described and named as new species. In a recent paper published in Frontiers in Zoology we review concepts of Integrative Taxonomy and propose a consensus work protocol that combines evidence from multiple data sources for the identification of new species. We argue that taxonomy needs to be pluralistic and integrate new approaches for species delimitation if it is to become a modern evolutionary discipline, and that new methods of automation need to be tested to overcome the bottleneck of actually scientifically naming and describing the many candidate species that are routinely discovered by DNA barcoding studies.
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A Rhapsody of Colours
Taxonomic revisions are always a prominent part of our work, but rarely as exciting as the recent discovery of an extremely colourful new species of snake from Madagascar, which we described as Liophidium pattoni. In fact, this species had been photographed several times before, but no specimens had become available to us previous to our own survey in the newly created Makira reserve in 2009.
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Undescribed Frog Diversity and Candidate Species
In a recent paper published in PNAS, we report on an unprecedented 
number of new species of frogs that we discovered in Madagascar using an integrated approach that combined an initial DNA barcode screening followed by focused bioacoustic and morphological comparisons. The results indicate the existence of an almost 2-fold increase in species numbers from the currently described 244 species to a minimum of 373 and up to 465. For the original article in PNAS, see here. For a selection of press coverage of this paper, see here.
Vieites, D.R., K. C. Wollenberg, F. Andreone, J. Köhler, F. Glaw & M. Vences (2009): Vast underestimation of Madagascar's biodiversity evidenced by an integrative amphibian inventory. Proc. Natl. Acad. Sci. U.S.A. 106: 8267-8272.
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Conserving Madagascar's Megadiverse Biota
With a team of researchers led by Claire Kremen and Alison Cameron from the University of California, Berkeley, we have recently translated our biogeographic and systematic amphibian data gathered over 15 years into precise conservation planning. As reported in the cover article of the 11 April 2008 issue of Science, distribution models and point distribution data of altogether over 2300 animal and plant species were used to determine priority areas for biodiversity conservation in Madagascar, and to propose new areas to be included in Madagascar's reserve network.
In a further recent paper in the "Perspectives" section of PLoS Biology, we argue that that proactive conservation efforts should be focused on Madagascar's amphibians, as this hyperdiverse fauna so far appears to be untouched by emergent diseases but will become highly threatened in the near future due to habitat destruction.
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Andreone, F., A. I. Carpenter, N. Cox, L. du Preez, K. Freeman, S. Furrer, G. García, F. Glaw, J. Glos, D. Knox, J. Köhler, J. R. Mendelson III, V. Mercurio, R. A. Mittermeier, R. D. Moore, N. H. C. Rabibisoa, H. Randriamahazo, H. Randrianasolo, N. Rasomampionona Raminosoa, O. Ravoahangimalala Ramilijaona, C. J. Raxworthy, D. Vallan, M. Vences, D. R. Vieites, C. Weldon (2008): The challenge of conserving amphibian megadiversity in Madagascar. – PLoS Biology 6: e118.
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Identifying Species in Madagascar's Herpetofauna
The third edition of our Field Guide to the Amphibians and Reptiles of Madagascar is available since October 2007 from Chimaira. The book has also been published as local language edition in Malagasy, financed through the World Bank Local Language Fieldguide Program. A full PDF of the Malagasy language version is available here.
Glaw, F. & M. Vences (2007): A Field Guide to the Amphibians and Reptiles of Madagascar. Third Edition. – Köln, Vences & Glaw, 496 pp. (ISBN 978-3-929449-03-7).
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See Sample Pages of the Field Guide
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Speciation in Amphibians
An extensive summary of current knowledge on mechanisms of species formation prevalent in amphibians was published in 2007 in the book series "Amphibian Biology", by M. Vences and D. B. Wake. The chapter also includes a survey of studies of phylogeography in amphibians, and tries to outline major promising fields of further research.
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Intercalary Element Evolution
Mantellid
frogs from Madagascar are characterized by a particular osteological
feature, the so-called intercalary elements between terminal and subterminal
phalanges of fingers and toes. Mantellids contain one lineage (Laliostoma
labrosum) without such intercalary elements and thereby provides the clearest example of secondary loss of this character. I recently contributed to a paper by Adriana Manzano and Marissa Fabrezi that studies the morphology of these skeletal elements and associated muscles across a wide taxon sampling of Recent anurans, and interprets the presence of these elements - or of its developmental genetic basis - as morphological novelty that originated early in the Neobatrachia.
Manzano, A., M. Fabrezi & M. Vences (2007): Intercalary elements, treefrogs, and the early differentiation of a complex system in the Neobatrachia. – The Anatomical Record 290: 1551-1567.
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Neotropical Amphibian Diversity Underestimated
The integration of molecular, biocoustic and morphological data have shown
that a very large number of undescribed amphibian species occurs
in Madagascar. Antoine Fouquet has analyzed molecular data from Neotropical
amphibians to obtain first estimates of cryptic diversity, and besides
distance-based and phylogenetic analyses also developed a method to analyse
cross-species data for isolation-by-distance and thereby isolate signals
of cryptic species. In a joint paper we estimate that Neotropical amphibian
diversity is severely underestimated, but also present evidence that genetically
similar populations of widespread species do exist in South America.
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Web by Sandra Nieto
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