About

Professor Roger Buick is a faculty member in the Department of Earth & Space Sciences at the University of Washington, specializing in astrobiology with a focus on the origin and earliest evolution of life on Earth. His research techniques intersect geology, biology, and chemistry, examining the oldest and best-preserved rocks from various locations including the Australian outback, Greenland ice-cap, South African veld, and Canadian woods. His work aims to understand when the main forms of microbial metabolism first arose, how early atmospheric conditions were modulated, and how these factors influenced environmental change in Earth's history. Professor Buick's research encompasses multiple projects such as studying the early evolution of bacterial metabolism through paleontology and stable isotope geochemistry, investigating early atmospheric composition and pressure via mineral and sediment analysis, and analyzing secular trends in marine nutrient fluxes to understand ecosystem evolution. He also explores the early evolution of continental crust through geochemical analysis, and searches for molecular fossils in Precambrian rocks to uncover organic biomarkers that inform the phylogenetic history of microbial ecosystems. His contributions have advanced understanding of Earth's early atmosphere, biosphere, and tectonic development, providing insights into the conditions that fostered the emergence of life and its evolution over billions of years.

Research topics

• Earth science
• Geology
• Geochemistry
• Astrobiology
• Paleontology
• Meteorology
• Physics
• Atmospheric sciences
• Environmental science
• Environmental chemistry
• Chemistry
• Geography

Selected publications

• Resurrected nitrogenases recapitulate canonical N-isotope biosignatures over two billion years

  Nature Communications · 2026-01-22 · 1 citations

  articleOpen access

  Nitrogen isotope fractionation (ε15N) in sedimentary rocks has provided evidence for biological nitrogen fixation, and thus primary productivity, on the early Earth. However, the extent to which molecular evolution has influenced the isotopic signatures of nitrogenase, the enzyme that catalyzes the conversion of atmospheric nitrogen (N₂) to bioavailable ammonia, remains unresolved. Here, we reconstruct and experimentally characterize a library of synthetic ancestral nitrogenase genes, spanning over 2 billion years of evolutionary history. We assess the resulting ε¹⁵N values under controlled laboratory conditions. All engineered strains exhibit ε15N values within a narrow range comparable to that of modern microbes, suggesting that molybdenum (Mo)-dependent nitrogenase has been largely invariant throughout evolutionary time since the origins of this pathway. The results of this study support the early origin of molybdenum nitrogenase and the resilience of nitrogen-isotope biosignatures in ancient rocks, while also demonstrating their potential as powerful tools in the search for life beyond Earth. The study shows that nitrogenase enzymes have maintained stable isotope signatures over billions of years, revealing how ancient microbes shaped Earth’s nitrogen cycle and offering a new experimental framework for probing early life.

  PublisherOA PDFDOI

• Resurrected nitrogenases recapitulate canonical N-isotope biosignatures over two billion years

  bioRxiv (Cold Spring Harbor Laboratory) · 2025-05-26

  preprintOpen access

  SUMMARY Nitrogen isotope fractionation (ε 15 N) in sedimentary rocks has provided evidence for biological nitrogen fixation, and thus primary productivity, on the early Earth. However, the extent to which molecular evolution has influenced the isotopic signatures of nitrogenase, the enzyme that catalyzes the conversion of atmospheric nitrogen (N 2 ) to bioavailable ammonia, remains unresolved. Here, we reconstruct and experimentally characterize a library of synthetic ancestral nitrogenase genes, spanning over 2 billion years of evolutionary history. By engineering modern microbes to express these ancient nitrogenases, we assess the resulting ε 15 N values under controlled laboratory conditions. All engineered strains exhibit ε 15 N values within a narrow range comparable to that of modern microbes, suggesting that molybdenum (Mo)-dependent nitrogenase has been largely invariant throughout evolutionary time since the origins of this pathway. These results confirm the robustness of N-isotope biosignatures in the ancient rock record and bolster their utility in the search for life in extraterrestrial environments.

  PublisherOA PDFDOI

• Controls of Ancient Geochemical Records: Global Oceans Versus Local Water Masses

  2025-01-01

  article
  PublisherDOI

• Mid-Devonian ocean oxygenation enabled the expansion of animals into deeper-water habitats

  Proceedings of the National Academy of Sciences · 2025-08-25 · 4 citations

  articleOpen accessSenior author

  The oxygenation history of Earth’s surface environments has had a profound influence on the ecology and evolution of metazoan life. It was traditionally thought that the Neoproterozoic Oxygenation Event enabled the origin of animals in marine environments, followed by their persistence in aerobic marine habitats ever since. However, recent studies of redox proxies (e.g., Fe, Mo, Ce, I) have suggested that low dissolved oxygen levels persisted in the deep ocean until the Late Devonian, when the first heavily wooded ligniophyte forests raised atmospheric O 2 to modern levels. Here, we present a Paleozoic redox proxy record based on selenium enrichments and isotope ratios in fine-grained siliciclastic sediments. Our data reveal transient oxygenation of bottom waters around the Ediacaran–Cambrian boundary, followed by predominantly anoxic deep-water conditions through the Early Devonian (419 to 393 Ma). In the Middle Devonian (393 to 382 Ma), our data document the onset of permanent deep-ocean oxygenation, coincident with the spread of woody biomass across terrestrial landscapes. This episode is concurrent with the ecological occupation and evolutionary radiation of large active invertebrate and vertebrate organisms in deeper oceanic infaunal and epifaunal habitats, suggesting that the burial of recalcitrant wood from the first forests sequestered organic carbon, increased deep marine oxygen levels, and was ultimately responsible for the “mid-Paleozoic marine revolution.”

  PublisherDOI

• Identification of micrometeorite candidates in altered 1.45 Ga Mesoproterozoic carbonates

  2024-01-01

  articleOpen access
  PublisherOA PDFDOI

• Nitrogen isotopes reveal independent origins of N2-fixing symbiosis in extant cycad lineages

  Nature Ecology & Evolution · 2023-11-16 · 14 citations

  articleOpen accessSenior author
  PublisherOA PDFDOI

• Technical comment on “Reexamination of 2.5-Ga ‘whiff’ of oxygen interval points to anoxic ocean before GOE”

  Science Advances · 2023-04-07 · 23 citations

  articleOpen access

  Many lines of inorganic geochemical evidence suggest transient “whiffs” of environmental oxygenation before the Great Oxidation Event (GOE). Slotznick et al. assert that analyses of paleoredox proxies in the Mount McRae Shale, Western Australia, were misinterpreted and hence that environmental O 2 levels were persistently negligible before the GOE. We find these arguments logically flawed and factually incomplete.

  PublisherOA PDFDOI

• Progressive Planetary Oxygenation: Multiple Lines of Evidence Confirm an Archean Oxidation Event at 2.5 Ga

  2023-01-01

  articleOpen access
  PublisherOA PDFDOI

• A shale-hosted selenium isotope record of Paleozoic ocean oxygenation

  Goldschmidt2022 abstracts · 2022-01-01

  articleOpen accessSenior author
  PublisherOA PDFDOI

• Mercury abundance and isotopic composition indicate subaerial volcanism prior to the end-Archean “whiff” of oxygen

  Proceedings of the National Academy of Sciences · 2021 · 55 citations

  Senior authorCorresponding
  • Geochemistry
  • Geology
  • Environmental chemistry

  sinks, followed by enhanced nutrient supply to the ocean from weathering of volcanic rocks causing increased biological productivity.

  PublisherOA PDFDOI

Recent grants

• COLLABORATIVE RESEARCH: Presaging Paleoproterozoic Global Change: Geobiology of the Late Archean Eon

  NSF · $80k · 2004–2008

• Selenium biogeochemistry as a deep-time redox proxy and biosignature

  NSF · $300k · 2009–2014

Frequent coauthors

• Eva E. Stüeken

  University of St Andrews

  159 shared

• Michael A. Kipp

  88 shared

• Ariel D. Anbar

  University of Louisiana at Lafayette

  81 shared

• Alan J. Kaufman

  73 shared

• Timothy W. Lyons

  69 shared

• Jessica Garvin

  68 shared

• Gail Lee Arnold

  The University of Texas at El Paso

  68 shared

• David C. Catling

  Earth and Space Research

  65 shared

Labs

• Roger Buick LabPI

Education

• Ph.D., Astrobiology

  University of Washington

  2000

• M.S., Astronomy

  University of Washington

  1994

• B.A., Physics

  University of California, San Diego

  1991

Awards & honors

• Fellow of the Geological Society of America (2019)