Current / Past Research / Research By Category

Research 08.08.14

Over the last few years we have explored the patterns and processes of morphological character evolution and species-level diversification, focusing on understanding the biogeographic and evolutionary histories of Southeast Asian amphibians and reptiles.  Biodiversity in many complex landscapes is likely affected by similar geologic events and climatic changes. We am now pursuing several broader, more comparative approaches to understanding mechanisms driving diversification, and...


Publications 09.15.13

Approximate Bayesian computation (ABC) is rapidly gaining popularity in population genetics. One example, msBayes, infers the distribution of divergence times among pairs of taxa, allowing phylogeographers to test hypotheses about historical auses of diversification in co-distributed groups of organisms. Using msBayes, we infer the distribution of divergence times among 22 pairs of populations of vertebrates distributed across the Philippine Archipelago. Our objective...


Publications 09.15.12

We report new distribution records for amphibians and reptiles from 20 localities within the northern Cordillera Mountain Range of Ilocos Norte Province, Luzon Island, Philippines. Together with opportunistic collections of specimens from past surveys, our new data result in a total of 58 amphibian and reptile species for Ilocos Norte Province and the extreme northern Cordilleras—all of which constitute major geographic range...


Publications 09.12.12

Aim We examine the genetic diversity within the lizard genus Gekko in the Philippine islands to understand the role of geography and geological history in shaping species diversity in this group.Wetest multiple biogeographical hypotheses of species relationships, including the recently proposed Palawan Ark Hypothesis. Location Southeast Asia and the Philippines. Methods Samples of all island endemic and widespread Philippine Gekko species were...


Publications 09.15.11

The spectacular, virtually endemic radiation of Philippine semi-fossorial skinks of the genus Brachymeles represent one of the few radiations of scincid lizards to possess both fully limbed and limbless species. And yet, nothing is known of the phylogenetic relationships of this exceptional group. Morphologically similar body plans have made it difficult to assess species-level diversity, and the genus has long been recognized...


Publications 09.12.11

We investigated phylogeography of Philippine slender toads (genus Ansonia) and used a temporal framework for diversification, statistical tests of alternate topologies, and Bayesian approaches to test previous hypotheses concerning dispersal to, and colonization routes within, the southern Philippine island of Mindanao. Two species of Ansonia previously have been documented, with ranges separated by an east–west split corresponding to the approximate boundaries of...


Publications 09.12.10

As humans continue to explore the last uncharted regions of the planet, discoveries of previously unknown species of large vertebrates have become infrequent. Here, we report on the discovery of a spectacular new species of giant, secretive, frugivorous, forest monitor lizard (Genus: Varanus) from the forests of the northern Philippines. Using data from morphology and mitochondrial and nuclear DNA sequences, we demonstrate...


Publications 09.12.10

In the Philippines, Pleistocene sea level oscillations repeatedly connected and isolated neighboring islands. Hence, an understanding of the island platforms adjoined during periods of low sea level has led biologists to a suite of expectations that, taken together, represent a paradigm for the process of recent diversification in southeast Asia. We employ statistical tests of phylogenetic topology and population genetic analyses of...