3 ms·

I went to a biology/astronomy talk where there was a researcher working on the sequence of chemical changes on the early earth without much water or atmosphere

I went to a biology/astronomy talk where there was a researcher working on the sequence of chemical changes on the early earth without much water or atmosphere would need to create dna base pairs. It was stunning because they basically had a sequence of things and geological discoveries point toward the precursor chemicals being available. It's not that dna was just there. This is not "life arising spontaneously". This is chemicals in an environment where they eventually build dna base pairs. Then after millions of years, perhaps you get microbes and go from there. Meanwhile we are getting water on earth from comets crashing down.

superposeur 3y ago
The “eventually build dna base pairs” (that continue self replicating) is the uncertain and possibly ludicrously improbable step. See for instance https://www.nature.com/articles/s41598-020-58060-0 https://www.nature.com/articles/s41598-020-58060-0 which argues for a probability per exoplanet small enough that it hasn’t happened a second time in the observable universe. On the other hand, one of the self-organizing proposals cited elsewhere in this thread may turn out to be correct and the probability may be much higher. The point is that, while there are some cool ideas on the table, everything hinges on the particular value of this probability (not just a qualitative story of how life might have arisen) and we don’t know what it is. Still relevant: https://blogs.scientificamerican.com/cross-check/pssst-dont-tell-the-creationists-but-scientists-dont-have-a-clue-how-life-began/ https://blogs.scientificamerican.com/cross-check/pssst-dont-...
- NotSammyHagar 3y ago
  Sorry, I didn't see your posting before. The person speaking at the astronomy on tap presentation made it seem much more likely, basically given expected conditions on pre-biotic earth, very likely in a million year timeframe. I'm a software engineer so I don't readily admit I don't know what I'm talking about. Are you in the field and can maybe elaborate on your skepticism? This fellow was pretty certain they've worked out several likely possible paths. This was last year.
  - NotSammyHagar 3y ago
    typo "I readily admit that I don't know anything" ;-) And I have bad typing and proofreading skills!

superposeur 3y ago

The “eventually build dna base pairs” (that continue self replicating) is the uncertain and possibly ludicrously improbable step. See for instance https://www.nature.com/articles/s41598-020-58060-0 https://www.nature.com/articles/s41598-020-58060-0 which argues for a probability per exoplanet small enough that it hasn’t happened a second time in the observable universe. On the other hand, one of the self-organizing proposals cited elsewhere in this thread may turn out to be correct and the probability may be much higher. The point is that, while there are some cool ideas on the table, everything hinges on the particular value of this probability (not just a qualitative story of how life might have arisen) and we don’t know what it is. Still relevant: https://blogs.scientificamerican.com/cross-check/pssst-dont-tell-the-creationists-but-scientists-dont-have-a-clue-how-life-began/ https://blogs.scientificamerican.com/cross-check/pssst-dont-...

NotSammyHagar 3y ago
Sorry, I didn't see your posting before. The person speaking at the astronomy on tap presentation made it seem much more likely, basically given expected conditions on pre-biotic earth, very likely in a million year timeframe. I'm a software engineer so I don't readily admit I don't know what I'm talking about. Are you in the field and can maybe elaborate on your skepticism? This fellow was pretty certain they've worked out several likely possible paths. This was last year.
- NotSammyHagar 3y ago
  typo "I readily admit that I don't know anything" ;-) And I have bad typing and proofreading skills!