4 ms·

The striking thing about this prediction if true is that it didn't evolve on the Earth.

by pg 13y ago

jeremyswank 13y ago
Either that, or our methods for dating geological strata are flawed.
- rimantas 13y ago
  Or that article is simply crap as pointed in the top comment.
  - jeremyswank 13y ago
    Indeed, also possible.
edwinkite 13y ago
I am a postdoc working on planetary habitability. This arxiv paper is a mesh sieve masquerading as a boat. Complexity's rise is a messy business [1]. There's some evidence for steady progress, easy steps [2]. At the other extreme, the machinery of oxygenic photosynthesis came together once after an inexplicable billion-year delay and completely reset the biosphere. No oxygen, no complex-eukaryotes-with-twisty-genomes like you and me. Inference: that was an very improbable, difficult step, and we got lucky. Survivorship (as conscious, therefore complex creatures) biases everything we see on Earth. Nobody knows whether the origin of life was an easy or a difficult step. We don't have a geologic record of the origin of life. But the existence of even one difficult step is enough to prevent you from playing Moore's Law games. There ARE good papers in this field that get traction out of very little data [3]. There are also reasons to think that Earth life may have originated on Mars. Joe Kirschvink (Caltech) is the big advocate of this [4]. Continued Mars exploration could test this. Interstellar panspermia, on the other hand, is vastly improbable. -- [1] good (2001) review: http://wwworm.biology.uh.edu/evodevo/lecture26/carroll02.pdf http://wwworm.biology.uh.edu/evodevo/lecture26/carroll02.pdf [2] opinionated summary by Simon Conway Morris: http://www.amazon.com/Lifes-Solution-Inevitable-Humans-Universe/dp/0521603250 http://www.amazon.com/Lifes-Solution-Inevitable-Humans-Unive...) [3] my favorite is Brandon Carter's argument about the number of difficult steps in our evolution: http://www.jstor.org/stable/37419 http://www.jstor.org/stable/37419 [4] Kirschvink's argument: http://www.gps.caltech.edu/users/jkirschvink/pdfs/MarsOriginofLifeFinal.pdf http://www.gps.caltech.edu/users/jkirschvink/pdfs/MarsOrigin...

The striking thing about this prediction if true is that it didn't evolve on the Earth.

by pg 13y ago

The striking thing about this prediction if true is that it didn't evolve on the Earth.

jeremyswank 13y ago

Either that, or our methods for dating geological strata are flawed.

rimantas 13y ago
Or that article is simply crap as pointed in the top comment.
- jeremyswank 13y ago
  Indeed, also possible.

edwinkite 13y ago

I am a postdoc working on planetary habitability. This arxiv paper is a mesh sieve masquerading as a boat. Complexity's rise is a messy business [1]. There's some evidence for steady progress, easy steps [2]. At the other extreme, the machinery of oxygenic photosynthesis came together once after an inexplicable billion-year delay and completely reset the biosphere. No oxygen, no complex-eukaryotes-with-twisty-genomes like you and me. Inference: that was an very improbable, difficult step, and we got lucky. Survivorship (as conscious, therefore complex creatures) biases everything we see on Earth. Nobody knows whether the origin of life was an easy or a difficult step. We don't have a geologic record of the origin of life. But the existence of even one difficult step is enough to prevent you from playing Moore's Law games. There ARE good papers in this field that get traction out of very little data [3]. There are also reasons to think that Earth life may have originated on Mars. Joe Kirschvink (Caltech) is the big advocate of this [4]. Continued Mars exploration could test this. Interstellar panspermia, on the other hand, is vastly improbable. -- [1] good (2001) review: http://wwworm.biology.uh.edu/evodevo/lecture26/carroll02.pdf http://wwworm.biology.uh.edu/evodevo/lecture26/carroll02.pdf [2] opinionated summary by Simon Conway Morris: http://www.amazon.com/Lifes-Solution-Inevitable-Humans-Universe/dp/0521603250 http://www.amazon.com/Lifes-Solution-Inevitable-Humans-Unive...) [3] my favorite is Brandon Carter's argument about the number of difficult steps in our evolution: http://www.jstor.org/stable/37419 http://www.jstor.org/stable/37419 [4] Kirschvink's argument: http://www.gps.caltech.edu/users/jkirschvink/pdfs/MarsOriginofLifeFinal.pdf http://www.gps.caltech.edu/users/jkirschvink/pdfs/MarsOrigin...