American Society of Naturalists

A membership society whose goal is to advance and to diffuse knowledge of organic evolution and other broad biological principles so as to enhance the conceptual unification of the biological sciences.

Dr. Priyanga Amarasekare, Vice President of the ASN: Research Highlight

Posted on by the ASN Executive Committee and Mark McPeek

Priyanga Amarasekare (center) receiving the ESA's Robert H. MacArthur Award
Priyanga Amarasekare (center) receiving the ESA's Robert H. MacArthur Award

The scientific community has become aware in recent months about the disruption of Dr. Priyanga Amarasekare’s position as a Professor at UCLA, with articles in outlets such as Nature and The Chronicle of Higher Education discussing the impact on Dr. Amarasekare, her students, and their research program. The ASN cannot comment officially on a personnel issue when so many details are confidential and/or unknown. However, we can speak to our experience working with Dr. Amarasekare, who has been a dedicated and active participant of the ASN Executive Committee in her role as Vice-President of the Society since her tenure began in January, 2022. The ASN Executive Committee has been impressed with Dr. Amarasekare’s ability to take on the many duties of this role in an exemplary fashion despite the many difficulties she has experienced during that time period. Our interactions with Dr. Amarasekare have given us great respect for her integrity, character, and perseverance, as well as for her research and her extensive service to the ASN.

Throughout her career, Dr. Amarasekare has seamlessly integrated the development of models that capture the fundamental mechanisms of species interactions and the resulting community structure with critical empirical analyses of the predictions resulting from those models. Few scientists are able to simultaneously craft theoretical frameworks for exploring fundamental issues and then construct insightful empirical tests of the possibilities that emerge so with such fluidity.

Dr. Amarasekare (back row, third from right) with members of her lab
Dr. Amarasekare (back row, third from right) with members of her lab

Much of Dr. Amarasekare’s work explores how spatial heterogeneity in environmental conditions shapes the outcomes of multispecies interactions and thus the structure of communities across the landscape. Her early analyses focused on competitive coexistence in dispersal-linked patches, and she methodically added more species to the problem to understand how coexistence of species at multiple trophic levels is influenced by various types of spatial structures and various dispersal strategies of the species embedded in those food webs. She has also used these ecological structures to explore how the dispersal strategies of component species should evolve in response to the heterogeneity of species interactions they encounter across space. These theoretical explorations grounded empirical tests of the emerging patterns in experiments using parasitoids searching for their hosts in complex experimental landscapes. This work also provided recommendations for the design of marine reserves in which fish are subject to harvesting.

In recent years, Dr. Amarasekare‚Äôs work has turned to exploring the responses of communities across space to global warming. The foundational idea of her approach is that different types of interactions that shape the demography of species are underlain by traits that respond to increasing temperature in different ways. Her grounding mechanism is that the biochemical processes that underlie traits influencing maturation and physiological performance increase fitness with temperature up to a maximum, and then fitness precipitously declines with further temperature increases. In contrast, traits influencing reproduction and food consumption have a much slower decline in fitness as temperatures increase past the maximum fitness point. Which types of traits are most affected by the specific features of local temperature increases shape the demographic consequences for species of increasing temperatures. She is using these biochemical insights to build trait-based models of species with complex life histories to predict how species will respond to various scenarios of climate warming (e.g., various combinations of winter warming and summer temperature spikes). She is also extending these models to explore how vector-borne diseases may respond to these different scenarios of warming. The hallmark of this work is its grounding in the biochemical mechanisms underlying trait dynamics across temperature gradients and its application to real-world problems faced by species in real communities.

Dr. Amarasekare (second from right) with members of her lab
Dr. Amarasekare (second from right) with members of her lab

Dr. Amarasekare’s research has earned her several of the most prestigious awards in biology. These include the Young Investigator Award, which she received from the ASN in 2001, election as a Fellow of the Ecological Society of America in 2017, a Guggenheim Fellowship awarded in 2021, and the Robert H. MacArthur Award, granted by the Ecological Society of America in 2022.

Dr. Amarasekare has a long record of distinguished service to the ASN. Starting as a member in 1998, Dr. Amarasekare served from 2010–2012 as a member of the Early Career Investigator Award Committee. She served three consecutive terms as an Associate Editor of The American Naturalist, to which she has also contributed 10 papers [and counting] as an author. As a part of her tenure as the Vice President, an office that she assumed in 2022, Dr. Amarasekare hosted a symposium titled “From lower-level processes to higher-level patterns: a mechanistic understanding of emergent properties” at the Evolution meeting in June 2023. Five early career scientists, all from underrepresented groups, presented research under this broad theme, ranging from choromosome evolution in protocells to the impact of climate warming on plant-herbivore interactions from the Eocene to the present. A collection of articles based on the work presented at the symposium will be published as a special feature in The American Naturalist next year.