Originally posted by sonhouse
And a newer paper:
The old critics of the primordial soup showed that without an energy source, reactions couldn't take place. This new work says the hydrothermal vents we see all over the ocean bottom today was there billions of years ago also and provided t ...[text shortened]... n years ago, only a half billion years after Earth coalesced from the dust of the solar system.
I have only just read http://phys.org/news/2013-07-life-arose-earth.html for the first time and I think it is brilliant because it explains something that has been actually been personally puzzling me for some time which is the ridiculous way respiration works in nature.
When I study how respiration works in modern life, it appears totally crazy and stupid to the extreme! It is so indirect and appears unnecessarily complex. Of course, we should expect
evolution to often come up with stupid crazy arrangements like this! But, what kept bothering me about this is how ridiculously indirect and complex it is because I think, surely, it would have been vastly more likely that even evolution, totally blind as it is, would have much more likely have come up with something simpler and direct than this albeit still less than perfect? I mean, just look at the crazy way how respiration normally works: first sugar is oxidised and the chemical energy is converted into electrochemical energy in a form of a proton gradient across a membrane; then that electrochemical energy is converted BACK into chemical energy! -in the form of ATP in this case. Then that chemical energy, is use to drive metabolism and is even sometimes converted into other forms of chemical energy! In the case of nerves generating electrical impulses, that chemical energy is converted BACK into electrochemical energy! Each energy conversion comes at a cost -some energy is always lost in the conversion. Thus, with all else being equal, each unnecessary energy conversation you add, you are adding an addition source of energy wastage and inefficiency.
But now we have an explanation why this crazy arrangement evolved (from the link ) and it makes perfect sense! The first electrochemical energy stage evolved first. Then, because evolution cannot do a complete overhaul of the system and generally cannot go one step back to go two steps forward in a different direction, life was stuck with this electrochemical energy stage and evolution built on top of this stage instead of doing the intelligent thing which would be a complete overhaul that involves replacing it rather than just adding to it. I now think this hypothesis is almost certainly correct.
Respiration in nature appears to be one of evolution's big blunders. To my mind, that opens up an interesting future possibility: we could artificially design life to have an intelligently designed reparation that skips the ATP step and uses the chemical energy in sugar more directly and thus with greater energy efficiency.