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.

2023 American Naturalist Student Paper Award

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Meredith A. Zettlemoyer
Meredith A. Zettlemoyer

The American Naturalist 2023 Student Paper Award is for work that was published in 2022 and that was performed primarily by the first author and primarily while she or he was an undergraduate or graduate student. The Editors of the journal, in consultation with Associate Editors, examine all student-authored papers in the journal to select an outstanding contribution that advances the journal’s goals of changing the way people think about organismal biology (including but not limited to ecology, evolution, and behavior) by providing new conceptual insights.


Zettlemoyer, Meredith A. 2022. “Monitoring demography of resurrected populations of locally extinct and extant species to investigate drivers of species loss.” The American Naturalist 200: E36–E51.

In this paper, Meredith Zettlemoyer poses an important question: why do some species go extinct with anthropogenic habitat changes while their close relatives persist? In the Anthropocene, communities are faced with a multitude of new disturbances and rapidly changing conditions that can lead to decline in natural populations and even extinction. But how can we determine what causes the differential extinction of species when they are no longer present in the community? Zettlemoyer overcomes this obstacle by conducting an ambitious experiment that reintroduces locally extinct species into the ecosystem to compare their demographic response to closely related sister taxa that persisted. Using sophisticated population models, she found that survival rates of locally extinct taxa were much more negatively affected by nitrogen deposition (a common effect of anthropogenic land use), despite potential positive effect on nitrogen on growth rates of individual plants. These results not only help explain why certain species have been lost from the local system, but also demonstrate how we can reveal the demographic differences between species that are successful in resisting anthropogenic disturbances and those that fail. The Editors of The American Naturalist were impressed with the creative question, elegant experimental design, and sophisticated population model and demographic analyses. This is a very nice example of how we can integrate experimental ecology with theory to tackle critical concepts in global change ecology, with important practical implications for the many conservation and management challenges we face today.

Honorable mention:

Bisschop, Karen, Adriana Alzate, Dries Bonte, and Rampal S. Etienne. 2022. “The demographic consequences of adaptation: evidence from experimental evolution.” The American Naturalist 199: 729–742.

Honorable mention goes to Karen Bisschop for the paper “The demographic consequences of adaptation: Evidence from experimental evolution.” When species invade new habitats, we expect that they acquire higher fitness through changes in life history traits. But how do these evolutionary changes affect the population dynamics of species? In this study, Bisshop and colleagues fit models to the dynamics of spider mite populations in immigration experiments to explore this connection between evolutionary and ecological dynamics. They found that adaptation increases population growth rates, but carrying capacity could either decrease or increase over time depending on the ecological conditions. Their work elegantly tests a complicated concept and provides clear evidence for the importance of evolution in driving population dynamics in changing environments.