Harry McClelland is a senior postdoctoral fellow and Dean’s fellow at the Weizmann Institute of Science. After graduating with a first-class MSc in Natural Sciences from the University of Cambridge and receiving an MSc with Distinction in Phylogenetics from Imperial College London, he received his PhD in 2016 from the University of Oxford, where he studied isotope geochemistry and paleoclimate under the supervision of Professor Ros Rickaby. He undertook a tenure as a postdoctoral research scholar at Washington University in St Louis, where he used geochemical tools and mathematical modelling to investigate metabolic heterogeneity in clonal microbial populations, working with Professors Alex Bradley and David Fike.
At the Weizmann Institute, Harry works in the areas of Earth History, Evolution and Isotope Geomicrobiology with Professor Itay Halevy. He summarizes his research as follows:
Stable isotope ratios are widely used to investigate the nature of life and the environment when these cannot be observed directly. Examples include: Earth’s geologic past; metabolism at the scale of individual cells; and locations that are impossible to reach, such as the deep subsurface and even other planets. However, extracting meaningful information about life or environment with isotopes requires a quantitative understanding of the filter through which we are making these observations. My research centers on mechanistically understanding this filter in various scenarios, using experiments and simple mathematical models. At present I am particularly interested in the effect of microbial mat metabolism on geochemical compositions preserved in the geological record, and the controls on carbon isotope fractionation during photosynthetic carbon fixation at the level of cellular metabolism. My wider interests include paleoclimate proxies for temperature and pCO2, life in the deep subsurface, population dynamics in bacteria and phytoplankton, and the interface between phenotypic plasticity and evolutionary adaptation across all spatial and temporal scales.