Russell Gray, Ph.D. - US grants

This INSPIRE award is partially funded by the Perception, Action, and Cognition Program in the Division of Behavioral and Cognitive Sciences in the Directorate for Social, Behavioral, and Economic Sciences and the Mathematical Biology Program in the Division of Mathematical Sciences in the Directorate for Mathematical and Physical Sciences.

This work explores the role of selection and adaptation in two radically different domains, 1) molecules and 2) languages. Consider, for example, human languages. The 6,000-7,000 languages spoken by people display a dazzling variety of sounds, words, and grammatical forms. This diversity is typically explained as a product of random drift: As a single population splits and drifts apart, the accumulation of small random changes eventually produces mutually unintelligible languages. An alternative is that some of the variation we see among human languages is due to selection. In this account, languages adapt to some extent to the different social and ecological environments in which they are spoken. Similarly, researchers have only recently considered the role of selection and adaptation in the study of prions (self-replicating proteins)and how they propagate within and across generations of cells.

Though biological structures and human languages are radically different domains, they share properties that suggest they may be described by a common mathematical framework. Specifically, (i) they are both epigenetically inherited, (ii) they both capitalize upon a pre-existing biological substrate, and (iii) they both propagate in a system of agents (cells, people). A highly interdisciplinary team of cognitive scientists, linguists, biologists, and mathematicians seek to connect and inform these domains by using mathematical models and large-scale behavioral experiments to understand the selective processes. They will assess convergent tests of the idea that selection acts as an organizing principle of systems at different scales. This work has important implications for issues such as the role of environmental context in the spread of structures such as prions or linguistic elements. For example, results could help explain how a structure newly infects populations, such as when a new word "invades" a linguistic environment, or when a prion structure successfully propagates and infects cells in its environment. The interdisciplinary nature of this award will provide a unique training experience for graduate students and will include outreach efforts to local schools.