Thomas Drant and Antonin Affholder have been named the new NOMIS–ETH Fellows at the Centre for Origin and Prevalence of Life (COPL) at ETH Zurich.
Supporting COPL’s interdisciplinary and collaborative effort to explore fundamental questions about how and why life began, the NOMIS–ETH Fellowship Program enables exceptional early-career researchers to examine these big questions, make connections, take risks and build bridges across the boundaries of disciplines.
Thomas Drant
Dr. Thomas Drant (pictured above, left) pursued his undergraduate studies at Sorbonne University in Paris, France, specializing in physics, geoscience, and planetary science. With a strong interest in climate science, atmospheric chemistry, and planetary habitability, he continued his academic path with a cotutelle PhD between the University of Paris-Saclay and Ludwig Maximilian University. He specifically designed this joint PhD to develop expertise in both experimental and modeling approaches.
His doctoral research focused on atmospheric chemistry, investigating the diversity of atmospheric compositions shaped by volcanic outgassing and the formation of solid organic hazes. These atmospheric hazes are believed to have played a crucial role in shaping early Earth’s climate and may have contributed to the emergence of life. As part of his work, Dr. Drant initiated a cross-laboratory collaboration with NASA Ames, conducting detailed analyses of the composition, morphology, and optical properties of organic haze analogs produced in laboratory experiments. In parallel, he used modeling techniques to explore the conditions under which methane-rich atmospheres could form through volcanic degassing, identifying planetary environments where active organic chemistry may be ongoing.
“I will explore how photochemical processes produce prebiotic molecules like HCN and H₂CO under different atmospheric conditions. By combining experiments with modeling, I aim to understand their role in planetary habitability and the origins of life.” —Thomas Drant
On 1 April 2025, Thomas Drant joined ETH Zurich in the Department of Earth and Planetary Sciences, under the mentorship of Prof. Paolo Sossi and Prof. Olivier Bachmann, and he will further develop the current photochemistry setup to investigate the formation of prebiotic precursors such as hydrogen cyanide (HCN) and formaldehyde (H₂CO). These compounds, produced by photochemical processes in planetary atmospheres, likely played a key role in the synthesis of more complex organic molecules necessary for the origin of life. His research will focus on understanding how the production of these precursors varies across different oxidation states and temperature regimes, identifying the conditions most favorable for their accumulation. By integrating atmospheric modeling with photochemical experiments, Dr. Drant aims to explore how these processes interact with planetary climate and transport mechanisms, ultimately shedding light on their influence on planetary habitability.
Antonin Affholder
Dr. Antonin Affholder (pictured above, right) became an evolutionary ecologist at École Normale Supérieure in Paris, France. During his PhD there, he applied tools from the theory of ecosystems to tackle inference of habitability and biosignatures. He developed models for the atypical microbial ecosystems which may have dominated the biosphere of Earth’s young years, and now populate the oxygen-less deep ocean and soils.
Using these models in conjunction with geochemical and geophysical modelling, Dr. Affholder was able to infer the likelihood of data gathered from space by the Cassini mission under the hypothesis of Earth-like hydrothermal microbes in Enceladus’s subsurface ocean. Using this modelling, he also constrained the potential for Titan’s ocean to harbour Earth-like life, and estimated the size that hypothetical biospheres in the oceans of icy moons could reach. Some of his other work is focused on the atmospheric evolution of Earth-like planets, researching signatures of habitability and inhabitation in atmospheric spectra that future telescope will acquire. In particular, he researched how a future telescope probing the atmosphere of Earth-like planets could infer whether an Earth-like carbon cycle is required to sustain a temperate climate over geological timescales. Dr. Affholder’s current postdoctoral research at the University of Arizona, Tucson, USA, focuses on the microbial ecology of soil communities and their participation to the Earth’s carbon cycle, specifically on how microbial adaptation affects soil biogeochemistry, and how evolutionary theory can be used to improve models of carbon cycling.
“I will investigate how geochemical and biological interactions delayed Earth’s oxygenation for millions of years. Understanding this complexity is key to interpreting future exoplanet oxygen detections and their potential link to life.” —Antonin Affholder
Starting in September 2025, Dr. Antonin Affholder will conduct his research in the Department of Environmental Systems Science, in the Ecosystems and Landscape Evolution Group led by Prof. Loïc Pellissier. He will investigate how complex feedbacks between the abiotic and biotic components of the early Earth system, as well as competition between different metabolisms may have participated to delay the oxygenation of Earth’s atmosphere by hundreds of millions of years after oxygenic photosynthesis emerged. This inherent system complexity raises the possibility that the timing of the oxygenation of Earth’s atmosphere is a particular rather than generic outcome of geochemical and biological processes interacting together on a rocky, Earth-sized, habitable-zone planet with life. Detection of O2 in exoplanet atmospheres is seen as a relatively achievable goal in the coming decades. But unless we gain a deeper understanding of the presence or absence of this gas in the atmosphere relates to the presence or absence of a biosphere at the planet’s surface, interpretation of these future observations will remain challenging.
About the Centre for Origin and Prevalence of Life
Established in 2022 at ETH Zurich in Switzerland, the Centre for Origin and Prevalence of Life aims to establish an ambitious and innovative collaboration between different disciplines to comprehensively address the fundamental questions about life and advance our understanding of the processes that led to the emergence of life. More than 40 research groups from seven departments will work together with their counterparts from around the world to investigate the origin of life on and beyond Earth.
Go to this ETH Zurich release: 2025 Cohort of the NOMIS-ETH Fellows
