What I Do
Julio A. Rivera
I'm an evolutionary biologist that is interested in understanding how biodiversity arises. I take a comparative approach to test evolutionary hypotheses about adaptation and speciation. Recently, I became interested in how geology interacts with biotic factors to generate new species.
About Me
I have been interested in life since I was a child, begging my parent to buy me dinosaur toys. As I grew older, my interest for life grew. After finishing high school in Silver Spring, MD, I decided to attend Rochester Institute of Technology were I was awarded my B.S. in Biology with a minor in criminal justice. At RIT, I worked with Larry Buckley where I developed an interest in evolution and phylogenetics. Later, I attended the University of Hawaii at Manoa were I was awarded my Ph.D. in the summer of 2017. My dissertation work, under Marguerite Butler, focused on understanding how biodiversity is generated in tropical islands. Currently, I'm a Postdoctoral Research Scholar at Arizona State University were I'm working with Emilia Martins to develop phylogenetic methods that would allow the reconstruction of ancestral ranges of taxa.
Papuan microhylid project
Papua New Guinea is one of the most biodiverse places on Earth but has largely remained understudied. My dissertation work focused on understanding how biodiversity arises in PNG. To study this, I used a large family of frogs, the Microhylidae. Papuan microhylids are unique in that they occupy almost the entire ecological breadth of anurans. They also possess morphologies that seem to be adapted to occupy distinct niches. In my disseration, I constructed a molecular phylogeny for half the family (~150 spp; Rivera et al. 2017). I also used collected morphological, ecological, and performance data to determine if traits are being driven my adaptation to distinct niches or via a stochastic process. I found that performance differs between ecological types and that these performances are achieved by evolving specialized morphologies. Lastly, the performances were ecologically relevant and can be used as a proxy for fitness.
Hawaiian Megalagrion damselfly project
The Hawaiian archipelago seems to promote unique and interesting taxa that are found nowhere else on Earth. One of these is the colorful, endemic genus of damselflies the megalagrion. The megalagrion come in an array of colors and utilize different habitats - boasting the world's only terrestrial damselfly. My work entailed understanding how the megalagrion partitioned the habitat so that species can live syntopically without competing with each other. I discovered the the megalagrion have evolve to use different light levels so that some live in bright habitats, some in medium light, and others in dark habitats (Henry et al. 2017). Furthermore, our group found that the megalagrion also possess eye morphologies that allow they to best navigate their disparate habitats (Scales and Butler 2016)
Sceloporus biogeography project
The genus of reptiles, Sceloporus, is speciose and can be found throughout North America and Central America. Despite having a large distribution, we are not certain where and how it evolved. I'm currently taking a comparative approach and developing novel phyogenetic techniques to understand how geology interacts with biotic factors to give rise to new species. Using ancient climate and incidence data, we hope to develop an approach that will help us recreate ancestral ranges of Sceloporus so that we can understand how geology contributes to the generation of biodiversity
Would you like to learn more about my research projects?
Contact Me
Julio Rivera, Ph.D.
Postdoctoral Scholar
School of Life Sciences
Arizona State University
427 E. Tyler Mall
Tempe, AZ 85287