Southeast Asian Phylogeography
Southeast Asia is a complicated region that consists of a mainland with thousands of associated islands, some of which are oceanic islands (never connected to the mainland) while others are continental shelf islands (connected to the mainland when sea levels are low). As a result, the phylogeography in the region is extremely complicated. Additionally, many mammals, including the primates, in the region are extremely endangered. Therefore, I apply ancient DNA/next generation sequencing techniques to dried tissues from 50-150-year-old museum specimens mainly to trace phylogeographic patterns throughout the region. I also work with collaborators to apply the genomic results to conservation efforts in Southeast Asia, control for phylogenetic relatedness in comparative studies, examine natural hybrid populations, and test for positively selected regions of the genome.
The Island Rule
The “island rule” is a generalization which states that over evolutionary time on islands, small-bodied species become larger and large-bodied species due to a suite of ecological pressures. However, this phenomenon is debated as a rule largely due to differences in the methods used along with issues surrounding the phylogenetic relationships between insular and mainland organisms. Additionally, it is unclear how certain anatomical parts evolve with changes in body size. I am interested in examining the universality of the “island rule” within species and between very closely related species in Southeast Asia as it is a region where there are thousands of islands of various sizes and types. Moreover, I use a combination of allometric scaling and 3D morphometrics to examine evolutionary differences in the anatomical parts, such as brain size, tooth dimension, and skull shape, of insular organisms.
Through my studies looking at different populations on islands, I became very interested in variation both within species and between species. My research on this front spans a variety of topics, from variation in relative brain size of gibbons to bacula (penis bone) shape across primates to scapula shape in cliff-climbing langurs.