ASTRO-110 Lecture Notes - Lecture 12: Carbon-12, Chemotroph, Stromatolite
9 Sep 2020
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Document Summary
Certain microbes of domain archaea can survive in >100 c temperatures and no sunlight near underwater volcanic vents (black smokers) Different colours are from different bacteria in water of different temperatures. Organisms that survive in extreme environments are called extremophiles. Other extremophiles survive in the cold, dry deserts of antarctica . Or in environments that are far too acidic, alkaline, salty, or radioactive. Certain microbes can even survive deep underground. Endoliths have been found up to 3 km under the surface. Others create endospores resting pods that allow them to stay dormant to survive extreme conditions: Lack of water, extreme temperatures, poisons, vacuum of space. Extreme environments are much more common than those suitable for humans: Humans can only tolerate a very limited environment. Search for life elsewhere needs to include extremophiles. Range of life-sustaining conditions may be much broader than that suitable to humans. Three lines of evidence that life began between 3. 85 byr and 3. 0 byr ago.
