Hilton Oyamaguchi, PhD.
Evolutionary Ecologist
PROJECTS
I have been working along the gradient between the Amazon and the Brazilian savanna (Cerrado) in South America using anurans as a model to understand the importance of natural selection in the diversification process. In addition, I've been investigating acclimation and thermal tolerance in the túngara frog from Central America to better understand the physiological responses of tropical anurans to global warming. Currently, I am working along the altitudinal gradient in Bioko Island in Equatorial Guinea and the rainforest-savanna gradient in Cameroon to continue investigating the importance of ecological factors in the diversification process of ectothermic tetrapods. This study will enhance our understanding of how this astonishing tropical biodiversity evolved and it will help to make better predictions of the effects of climate change.
Diversification Process in Central Africa
The Cameroon Volcanic Line presents a fascinating geography of sky islands in the continent, oceanic islands (São Thomé, Principe, and Annobón), and one land-bridge island (Bioko) with a high taxonomic diversity of endemisms. The Cameroon Volcanic Line in the Gulf Guinea and mainland Cameron may have acted as regions of diversification. The combination of a heterogeneous tropical landscape, and geographic isolation of the oceanic islands to west coastal Africa, and the sky islands with a steep elevational gradient has been proposed as the main drivers that have shaped the patterns of diversity in this region. The complex topography and ocean isolation may cause restriction to gene flow and strong environmental gradient may result in adaptive divergence resulting in speciation events. This complex geography in this volcanic line provides an exceptional natural laboratory for investigating the interplay of natural selection, genetic drift and gene flow across the speciation continuum.
Conservation Biology
Predicting the consequences of global climate change in amphibian populations.
Understanding how temperature affects amphibian populations is fundamental to predict the consequences of global climate change. Global mean surface temperatures are projected to continue increasing, and precipitation differences between wet and dry seasons are likely to become more pronounced. We want to investigate whether amphibians can metabolically cope with ongoing climate change and if they are able to adapt to new environmental conditions.
-Thermal sensitivity of tropical amphibians
Methods development
Weather station for field research
We are developing an automatic weather station using the Arduino and respective sensors available. While this type of data can be collected with existing high-cost meteorological equipment, we are putting effort to develop a weather station that will be able to collect accurate and reliable data for less than $100. These environmental factors loggers are often needed in field research projects and long term scientific monitoring.
