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.
See Team Research Plan |