Paper
22 September 2005 Extremophiles, survivophiles, and the continuity of life on Earth
Carol Chao, Carissa E. Chu, Jonathan D. Trent
Author Affiliations +
Abstract
In this paper we describe "extremophiles" and "survivophiles" and consider their role in the continuity and perpetuity of life throughout Earth's turbulent history. The term "extremophiles" refers to organisms active in what are considered by human beings to be extreme physical or chemical environments. The term "survivophiles" collectively refers to organisms capable of assuming reversible inactive states (suspended or latent), which enable them to survive harsh conditions until what they consider hospitable conditions to metabolic activity return. We present the various biological states of individual organisms (active, inactive, transition) and how these states relate to the dynamic biological-physicalchemical context that makes up an organism's environment. We argue that within these states the special adaptations of extremophiles and survivophiles have allowed life as a phenomenon to withstand global catastrophes, which include massive volcanic eruptions, supernovae explosions, and asteroid impacts. These are the catastrophes that changed the environments on Earth too quickly for organisms to adapt by Darwinian evolution. We suggest that genetic adaptations of extremophiles both allow them to thrive under at least some of the harsh conditions caused by catastrophes and these same adaptations also make them a source of genetic information for intrinsically stable macromolecules. This genetic information for stable macromolecules can be shared with other organisms through lateral gene transfer. Similarly, the adaptations of survivophiles increase survival during catastrophes and provide a source of genes for bio-stabilizing molecules (e.g., heat shock proteins, trehalose and other organic solutes). We conclude that the strategies and the specialized genes for growth and survival of extremophiles and survivophiles impact the continuity and perpetuity of life during global catastrophes by expanding the range of possible refugia during these events and by providing genetic information to other organisms.
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Carol Chao, Carissa E. Chu, and Jonathan D. Trent "Extremophiles, survivophiles, and the continuity of life on Earth", Proc. SPIE 5906, Astrobiology and Planetary Missions, 59060B (22 September 2005); https://doi.org/10.1117/12.626561
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KEYWORDS
Organisms

Genetics

Macromolecules

Proteins

Bacteria

Atmospheric particles

Planets

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