"Would a bird be able to fly in zero-gravity, or does it need gravity to fly? Have any experiments been done with live birds in outer space?"
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Project Investigators: Lee Kump
Other Project Members
Ariel Anbar (Collaborator)Michael Arthur (Collaborator)Donald Bryant (Collaborator)Katherine Freeman (Collaborator)Lev Horodyskyj (Doctoral Student)Christopher House (Collaborator)Christopher Junium (Collaborator)Jennifer Macalady (Collaborator)Katja Meyer (Doctoral Student)Dave Pollard (Collaborator)Greg Retallack (Collaborator)Anthony Riccardi (Doctoral Student)William Seyfried (Collaborator)Summary
We are exploring the geological and geochemical record of ancient Earth for clues about the co-evolution of life and environment. We’re focusing on three events in Earth history: the apparent rise of atmospheric oxygen at 2.45 billion years ago, the establishment of life on land during the Cambrian (about 540 milliion years ago), and the greatest mass extinction of all time at the end of the Permian, 252 million years ago. We use a combination of computer modeling, field work, and laboratory analysis.
Astrobiology Roadmap Objectives:
- Objective 4.1: Earth's early biosphere
- Objective 6.1: Environmental changes and the cycling of elements by the biota, communities, and ecosystems
- Objective 7.1: Biosignatures to be sought in Solar System materials
- Objective 7.2: Biosignatures to be sought in nearby planetary systems
Project Progress
Our hypothesis concerning the evolution of atmospheric oxygen, based on analysis of existing data, has been published in two articles appearing in Nature and Science. We link the rise of oxygen to the establishment of large and thick continents and associated subaerial volcanoes at the end of the Archean.
Work on the evolution of terrestrial ecoystems has progressed well: we now have several well-characterized paleosols (ancient soils) from the the continental United States developed during the Cambrian “explosion” of biodiversity (in the marine realm); we’re addressing environmental and biotic change on land during this event. All soils exhibit extreme weathering depletion of major cations, perhaps consistent with the post-Snowball Earth supergreenhouse state of the Late Neoproterozoic and early Cambrian.
Finally, we’ve published two new papers on the Permian extinction and related anoxic ocean states, arguing that anoxia and the buildup of hydrogen sulfide might be more important than imagined for the end-Permian event and less important for the Proterozoic than envisioned. We have also established the biomarker distributions in a modern euxinic (H2S-rich) environment, learning that abundant green sulfur bacteria are not producing their characteristic biomarker isorenieratene, and that benthic forms of the purple sulfur bacteria produce okenone, in contradiction to recently published claims that okenone production is a planktonic PSB biomarker. This latter finding is especially important to our interpretation of biomarker distributions in ancient rocks.
Cross-Team Collaborations
I have been developing a future project with Ariel Anbar on the biogeochemistry of anoxic/euxinic environments, with a focus on Fayetteville Green Lake (NY State) as a Proterozoic ocean analog.
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- Castleman Report
- Evolution of a Habitable Planet (Brantley)
- Evolution of a Habitable Planet (Stewart)
- Examination of the Microbial Diversity Found in Ice Cores (Brenchley)
- Ferry Report
- Genomic Record of the Earth's Early Biosphere (Hedges)
- Genomics of sulfidic cave extremophiles (Supplement to NNA04CC06A)
- Laboratory Microbial Simulations: Astrobiological Signatures
- Modeling Early Atmospheric Composition and Climate
- Molecular Signatures of Life on the Edge (DDF project)
- PSARC (Sigurdsson report)