TEMPO AND MODE: USING GENOMIC, ANATOMICAL, AND LIFE-HISTORY DATA TO INTEGRATE THE MICRO- AND MACROEVOLUTION OF BIRDS

Abstract

My research agenda as a Ph.D. Candidate has been primarily driven by a fascination with the boundary between micro- and macroevolution. While these intellectual domains are most commonly studied separately from of one another, I do not regard them as products of distinct phenomena; to me, they are different manifestations of the same underlying evolutionary processes. As such, I am motivated to understand the mechanisms linking microevolutionary processes to macroevolutionary patterns. Some of the questions that guide my research program include: What are the roles of evolutionary contingency and convergence in generating patterns of biodiversity? Why might certain modes of evolution predominate over others? What are the drivers and constraints on evolutionary change? Are there evolutionary ‘laws’? My first two dissertation chapters focus on evolutionary questions at relatively recent timescales. The most significant of these interests focuses on the biogeography and evolution of neotropical suboscine passerines, a speciose group of modern birds representing ~10% of living bird diversity. In particular, I focus on two South American avian clades, Cotingidae (Berv and Prum 2014), and Pipridae (forthcoming work, Berv et al 20xx), which are characterized by a fascinating diversity of plumages, vocalizations, and display behaviors. These works evaluate several hypotheses about the origins of diversity in the Amazonian and Andean regions of Latin America. While the first half of my dissertation reports on avian microevolution, I am also deeply fascinated by macroevolutionary patterns. Birds are one of the most broadly appreciated groups of living organisms, but the origins of modern birds are shrouded in mystery. After the Chicxulub asteroid struck the Yucután peninsula 66 million years ago (the K-Pg event), up to 75% of life on Earth was lost. It took millions of years for ecosystems to recover from this geologically instantaneous contingency. We know that at least a few early lineages of modern birds survived and rapidly diversified in the wake of this event—but how? My dissertation research in this area leverages advances in DNA sequencing to investigate the impact of the mass extinction on bird evolution. In one chapter, I worked with a team of researchers to construct a new phylogenetic framework for understanding bird diversification (Prum, Berv et al 2015). In my final chapter (Berv and Field 2018), I propose and evaluate a new hypothesis—that the K-Pg event drove a macroevolutionary shift in the rate of avian genome evolution.