Divergence along an elevational gradient in Borneo

Divergence along an elevational gradient in Borneo

Elevational gradients and the divergence along them have IMG_0846taken an increasingly prominent role in biogeography because it is along these gradients that the effects of climate change can be most readily observed. My broad questions about these gradients include asking about what populations/colonies of a single species do differently as they move up in elevation. On the genetic level this means asking about population structure, gene flow and potential genetic divergence along these gradients.

With funding from the Lewis & Clark Fund for Exploration and Field Research, I traveled to Sarawak (Borneo) in 2012 to collect ants from high and low elevations. I focused on an area in Mulu National Park with two accessible mountains within close range of each other (Mt. Mulu:  2,376 m & Mt Api: 1,750 m). I focused on trap-jaw ants (species Odontomachus rixosus) and used chemical, morphological and genetic tools to investigate populations. I used nDNA and mtDNA markers to discern the evolutionary history of low and high elevation populations of what is currently a single named species.

The results show that there are several cryptic species within O. rixosus, each species with distinct morphological features and a distinct elevational range. The paper describing these findings is currently in preparation.

Odontomachus rixosus -- Mulu NP, Sarawak, Borneo

Odontomachus rixosus — Mulu NP, Sarawak, Borneo