NAS Award in the Evolution of Earth and Life

Established by the NAS Council in June 2017 by combining two awards: the Daniel Giraud Elliot Medal and the Mary Clark Thompson Medal. The award rotates presentation between the Elliot Medal that recognizes meritorious work in zoology or paleontology published no earlier than the last presentation of the medal (2018), and the Thompson Medal that honors important services to geology and paleontology. Each medal is presented with a $20,000 prize.

Terrie M. Williams, University of California, Santa Cruz, received the 2024 NAS Award in the Evolution of Earth and Life – Daniel Giraud Elliot Medal. Williams has made fundamental contributions to understanding how large mammals function in their diverse habitats that has transformed the field of ecological physiology.

Her research is dedicated to understanding the ecological significance of large, apex carnivores and their physiological adaptations necessary for species survival in a world that is constantly changing due to human impacts. Williams has investigated the metabolic, cardiovascular, neural, and thermal physiology of terrestrial and aquatic mammals, detailing how individual species are built and how their underlying physiology drives functional relationships between animals and their environment. She has developed novel micro-technologies for field measurements of the physiology of free-ranging mammals such as Arctic narwhals, sea otters, African lions, seals, and polar bears.

Watch Williams’ acceptance speech.

Shuhai Xiao, Virginia Tech, received the 2021 NAS Award in the Evolution of Earth and Life – Mary Clark Thompson Medal. Xiao is a renowned paleobiologist and geobiologist who studies the interactions between the biosphere and its environments at critical transitions in Earth history, particularly during the Ediacaran-Cambrian transition.

Xiao integrates geological, geochemical, and paleontological research on the evolution and radiation of eukaryotes, of algae, and of animals in the Ediacaran and Cambrian periods. Through this approach, his contributions at the interface of geology and paleontology have re-envisioned our understanding of the evolutionary transformation from the mainly microbial world of the Proterozoic to the diverse multicellular life of the Ediacaran and Cambrian periods.

Xiao also integrates paleobiological, sedimentological, and geochemical data to shed light on important evolutionary events (such as the origin and diversification of eukaryotes, multicellular organisms, and animals), their environmental contexts, and their geobiological consequences. Xiao has co-authored several books, edited volumes, and field guides along with his international collaborators. His leadership and his construction of a scientific and cultural bridge between China and the United States have greatly benefited both societies.

Watch Xiao’s acceptance speech.