People

David Johnston

johnston@eps.harvard.edu

Professor of Earth and Planetary Sciences

& Co-Director of Graduate Studies

He/Him/His Primary research interests: Isotope geochemistry and historical geobiology; re-animating ancient ecosystems and ocean chemistry using stable isotope systems, chemical speciation techniques, modern microbial experiments (for calibration) and...

Val Aguilar

vaguilar@g.harvard.edu

1st Year Ph.D Student

She/Her/Hers Val received her BS in Earth Sciences (paleobiology & geology) from UC Santa Barbara in 2021. As an RA at Johns Hopkins University, she became interested in using lab and field techniques to answer questions related to perturbations in...

Erin Beirne

Former Johnston Lab Manager

Now a Research Associate in marine environmental chemistry at Bigelow Laboratory for Ocean Sciences

Emma Bertran

ebertran@princeton.edu

Former gardute student

The intimate interaction between microbial life and earth leaves specific chemical signatures that record information on microbial activity, and paleo-environmental conditions. As a geobiologist, my goal is to interpret these signatures and reconstruct an...

Alex Bradley

Former Postdoctoral Fellow

Now on the faculty at Washington University at St Louis.

Amanda Calhoun

acalhoun@g.harvard.edu

Ph.D Student

She/Her/Hers Amanda received her B.A. in Chemistry and Earth Sciences from Dartmouth College in 2023. Her research has focused on understanding the relationship between archaeal lipid production and geochemical conditions in hydrothermal springs. At...

Alyssa Chan

alyssachan@college.harvard.edu

Former Undergraduate Thesis Student

Alyssa is a senior concentrating in Chemistry and Earth and Planetary Sciences, with a secondary field in the Comparative Study of Religion. She joined the Johnston group in Summer 2014. Her thesis research involves evaluation of organic molecules as...

Chloe-Rose Colombero

crcolombero@college.harvard.edu

Former Undergraduate Research Assistant

Chloé-Rose is a senior at Harvard College concentrating in Organismic and Evolutionary Biology with a secondary field in Earth and Planetary Sciences, focusing on marine sciences. She joined the Johnston group in the summer of 2020 to work on a...

Ben Cowie

Former Post-doctoral Fellow

Ben is an isotope geochemist with diverse interests in the Earth sciences. In the Johnston Group, he is currently exploring questions surrounding the evolution of the atmosphere and biosphere over the most recent billion years of Earth history using a...

Daniel Crocker

dcrocker@fas.harvard.edu

Postdoctoral Fellow

He/Him/His Dan is a stable isotope geochemist interested in the sources, transformations, and environmental cycling of organic matter in a variety of geochemical environments—from ancient meteorites to the modern Earth. He completed his Ph. D. at the...

Peter Crockford

peter.crockford@weizmann.ac.il

Post-doctoral Fellow

person

Vivien Cumming

Former Research Associate, Harvard University

Viv is a photographer, filmmaker and writer specialising in documenting Earth science stories and expeditions. After postdocs at McGill and Harvard, Viv moved into science communication and now works with top scientists from around the world to make their...