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Thread: Origin of life in and around hot springs on land – detailed hypothesis

  1. #1
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    Origin of life in and around hot springs on land – detailed hypothesis

    I wanted to share this hypothesis paper by Bruce Damer and David Deamer. It's been published in the journal Astrobiology, and is freely accessible online...

    The hot spring hypothesis for an origin of life

    Their paper is about how life could have got started on Earth in the Hadean period, approx 4 billion years ago; or on other worlds comparable to Hadean Earth.

    Key points:

    * Life begins in or around hot springs on land, where cycles of evaporating and soaking occur
    * Earliest precursors of life much simpler than living cells, but like living cells have an outer membrane of lipid, with other carbon compounds inside
    * Natural selection starts before genes — there's no need to assume a jump from non-evolving randomness to first genetic molecules
    * The paper proposes ways of testing whether the hypothesised steps could work.

    If the hypothesis is right, life is likely to emerge on worlds chemically similar to Hadean Earth, with liquid surface water and volcanic islands. It doesn't require a massively low-probability, once-in-the-multiverse event.

    But life could not emerge this way on worlds where liquid water is subsurface only (like Europa and Enceladus), or on ocean-covered worlds which don’t have islands (water worlds).

  2. #2
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    So a “cell” of sorts from just the right amount of chemicals forming a blister from wet/dry cycles could act like a tiny lab—break, then spread?

  3. #3
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    Quote Originally Posted by publiusr View Post
    So a “cell” of sorts from just the right amount of chemicals forming a blister from wet/dry cycles could act like a tiny lab—break, then spread?
    Sorta.

    But even before there is a cell stable enough to spread independently, the wet/dry cycles are causing a variety of temporary cell-like structures to form, merge together, break apart again... And in each cycle, chemicals that make these structures less stable are more likely than other chemicals to get washed away, while chemicals which help stability are more likely to get conserved...
    Last edited by Colin Robinson; 2020-Jun-16 at 03:08 AM.

  4. #4
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    Call it bio-percolation

  5. #5
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    A less-technical article about the new hypothesis and its implications. (My own work!)

    How Earth was able to produce life step by step, and which other worlds could have done the same. Looks like answers are emerging

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