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  2. Purple Earth hypothesis - Wikipedia

    en.wikipedia.org/wiki/Purple_Earth_hypothesis

    The Purple Earth Hypothesis (PEH) is an astrobiological hypothesis, first proposed by molecular biologist Shiladitya DasSarma in 2007, [1] that the earliest photosynthetic life forms of Early Earth were based on the simpler molecule retinal rather than the more complex porphyrin-based chlorophyll, making the surface biosphere appear purplish ...

  3. Earth system interactions across mountain belts - Wikipedia

    en.wikipedia.org/wiki/Earth_system_interactions...

    Earth systems across mountain belts include the asthenosphere (ductile region of the upper mantle), lithosphere (crust and uppermost upper mantle), surface, atmosphere, hydrosphere, cryosphere, and biosphere. Across mountain belts these Earth systems each have their own processes which interact within the system they belong.

  4. Great Oxidation Event - Wikipedia

    en.wikipedia.org/wiki/Great_Oxidation_Event

    The Great Oxidation Event (GOE) or Great Oxygenation Event, also called the Oxygen Catastrophe, Oxygen Revolution, Oxygen Crisis or Oxygen Holocaust, [2] was a time interval during the Earth's Paleoproterozoic era when the Earth's atmosphere and shallow seas first experienced a rise in the concentration of free oxygen. [3]

  5. Boring Billion - Wikipedia

    en.wikipedia.org/wiki/Boring_Billion

    The Boring Billion, otherwise known as the Mid Proterozoic and Earth's Middle Ages, is an informal geological time period between 1.8 and 0.8 billion years ago during the middle Proterozoic eon spanning from the Statherian to the Tonian periods, characterized by more or less tectonic stability, climatic stasis and slow biological evolution.

  6. Oxygen cycle - Wikipedia

    en.wikipedia.org/wiki/Oxygen_cycle

    Main reservoirs and fluxes — in the biosphere (green), marine biosphere (blue), lithosphere (brown), and atmosphere (grey). The major fluxes between these reservoirs are shown in colored arrows, where the green arrows are related to the terrestrial biosphere, blue arrows are related to the marine biosphere, black arrows are related to the lithosphere, and the purple arrow is related to space ...

  7. Biosphere - Wikipedia

    en.wikipedia.org/wiki/Biosphere

    Life forms live in every part of the Earth's biosphere, including soil, hot springs, inside rocks at least 19 km (12 mi) deep underground, and at least 64 km (40 mi) high in the atmosphere. [ 26 ] [ 27 ] [ 28 ] Marine life under many forms has been found in the deepest reaches of the world ocean while much of the deep sea remains to be explored.

  8. Ecosphere (planetary) - Wikipedia

    en.wikipedia.org/wiki/Ecosphere_(planetary)

    J.B. Lamarck defined the term biosphere. When modern biologists mention the biosphere they usually mean the best part of the Earth's crust, which is the lithosphere and hydrosphere, and of the lower parts of the Earth's lower parts, which is the troposphere. All these together and the living organisms make up the biosphere.

  9. Marine prokaryotes - Wikipedia

    en.wikipedia.org/wiki/Marine_prokaryotes

    Sea spray containing marine microorganisms, including prokaryotes, can be swept high into the atmosphere where they become aeroplankton, and can travel the globe before falling back to earth. The earliest evidence for life on earth comes from biogenic carbon signatures and stromatolite fossils discovered in 3.7 billion-year-old rocks.