| My amateur-pop-philosophy-science way of thinking of it is that the transition from low to high entropy creates all kinds of interesting and complicated physical patterns along the way. Enough time, and the right patterns, and self-replication could emerge. But it's the externally driven 'stirring' of the low->high entropy transition that makes this possible. That is, life exists at the barrier between active and cool energy states. Sun to atmosphere/surface, hot planet core to surface/ocean. It's a (extremely complicated) product of these transitions. So it's not so much about "how can this just happen by chance" as if you think about what life actually is -- a boundary condition between two entropy states -- it makes more sense: There is a stir stick spinning (solar energy & earth's core) in a very complicated long lasting layered beverage (our earth), and life is the clouds of pretty patterns as the layers mix. The self-replication doesn't happen without that stick being stirred. It's not magic, it's just really complicated. Biochemist Nick Lane writes quite a bit about the alkaline hydrothermal vent theory and it is very compelling. I don't know (bio)chemistry well enough to fully understand it but it's something like (please people who understand this better correct me...) a) Very early earth had the 'lucky' combination of active hot core and cool (but not frozen) water covered surface. b) In addition to 'hot smokers', 'warm' (e.g. closer to cell / body temperature) vents exist and existed on the ocean floor. c) The ocean water was relatively acidic compared to now. But the warm vents had alkaline chemistry. d) The specific chemical reactions involved (hand waving here) as the warm vents mixed with the ocean created complex molecules, some organic. And some of the products produced were capsules/bubbles with 'walls' similar in structure cells. e) There's (more hand waving) reactions that can happen across the walls and molecules produced inside the 'cell-like' things. f) At some point they 'escape' the vent and its energy source. And in escaping 99.999% of them 'die', but eventually one that escapes does so in a way that it can self-sustain from other energy sources. g) At the same time at some point those proto-cells develop RNA or RNA-like processes internally such that they can reproduce It's f->g that I guess is the confusing part for me. But work is being done in the lab to try reproduce this whole process. In any case eventually the sun and earth will die, all cell machinery will stop, and entropy will have finally had its way with us. It's not a self-sustaining automaton. It requires an externally driven energy transition. |