nai

Linking Our Origins to Our Destiny

The research efforts of the Ames Team integrate a variety of disciplines around three scientific themes that address the context for life, the origin and early evolution of life, and the future of life both on Earth and in the environment of space.

Context for Life

The Ames Team is investigating both the chemistry and the environments conducive to life’s origin. First, they are tracing, spectroscopically and chemically, the cosmic evolution of carbon compounds from the interstellar medium to protoplanetary nebulae, planetesimals, and finally onto habitable bodies. Second, this team is probing the history of abiotically produced molecules of biological significance. Both of these investigations rely on spectral and chemical studies of realistic, laboratory analogs tightly coupled with quantum chemical calculations followed by astronomical searches. A related line of research is addressing the habitability of planets by identifying and quantifying those factors that collectively determine the inner and outer limits of the circumstellar habitable zone. For example, (1) water must have been delivered to the planet; and (2) climatic conditions must allow surface liquid water to persist. Thus, the focus of this research is on the origin and physical state of water, a study that depends on the sources of the water, the cycling of water and other volatiles between the surface and interior of a planet, and the detailed climate of the planet.

Origin and Early Evolution of Life and its Biosignatures

Do all habitable planets in fact become inhabited? Members of the Ames Team are investigating specific aspects of this question that are amenable to computational and laboratory investigation. They are testing the hypothesis that the most primitive protocells were structures built of evolving components related to those present in contemporary cells, but functioning without genomic control. And, in addition, the Ames Team is defining simple biomolecular systems that are capable of performing essential cellular functions, and seek to identify the conditions under which they can work together in a cellular environment. Comprehensive studies are also examining early microbial ecosystems by combining paleohistorical studies with experimental investigation of representative contemporary microbial ecosystems, and with model building. An improved understanding of long-term evolution of our own biosphere and the biogeochemical cycles that influence the environment will be valuable to researchers as they assess the prospects for survival of other biospheres and to develop a strategy to find them by interpreting their biosignatures. Such biosignatures will assist the search for a potential Martian biosphere, and to recognize possible spectroscopic signatures of an inhabited planet around other stars. Related work by the Ames Team is investigating the effects of varying levels of oxygen upon the photochemistry of atmospheric constituents.

Future of Life

Research by the Ames Team is also examing the effects of rapid environmental change on ecosystem properties and the potential for survival and biological evolution beyond the planet of origin. They are defining environmental factors that drive ecological change in South America, and are also analyzing preserved records of past change to ultimately be capable of predicting future trends in the Earth’s ecology. Sub-groups of the team are, in addition, exploring the effects of various forms of radiation upon the survival of life in extreme environments, including space, and working to developing methods for assessing radiation damage, examining specific biota for radiation resistance, and exposure experiments that include space flight.