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Fossils. Micro or nano scale tracks of chemotropic entities. Unusual small geological features indicative of anything other than normal random chemistry going o

Fossils. Micro or nano scale tracks of chemotropic entities. Unusual small geological features indicative of anything other than normal random chemistry going on. We can see all this in the rocks around us. TFA is about finding such things in mines deep underground. Remarkably we can even find such evidence in fossils more than 3 billion years old. Yet.. the oldest things we find are microbial sedentary structures indicative of remarkably complex life: with genes, ribosomes, proteins, etc. We know this because those same life forms still exist today and leave pretty much exactly the same tell tale signs. We call them simple life, but that is just by comparison. They are insanely complex compared to the random geochemistry going on alongside them. Why don’t we find ANYTHING older than this which differs from expected geological features? Where are the fossils from the origin of life? Also, the oldest fossils we have are of an organism that still exists: simple life remarkably doesn’t get competed to extinction. It turns out that simpler life forms have some advantages from their simplicity allowing them to be more adaptive to micro niches. So why don’t we have extant examples of even simpler life forms, surviving where complex life doesn’t fare as well?

andrewflnr 7y ago
Possible answer: there was a hard takeoff in complexity between the first thing you can call life with a straight face and some minimal level of complexity you need to stay alive and spread in the real world. That minimal level of complexity characterizes the first organisms that show up in fossils. If it happened fast enough (maybe up to a couple million years, I dunno), there would be an infinitesimal amount of evidence that could easily be missed forever. If it only happened once, we would need to look at exactly the right rock, across the whole planet, with a microscope. Or it could already be recycled into the mantle. Ocean crust doesn't have a long lifespan, IIRC. Dunno about the rest, but I do think that rapid advancement from proto-life to something pretty sophisticated is likely, wherever it starts.
ajuc 7y ago
Do we even know what we're looking for? Maybe some expected geologic features are the fossils of the first life? How do we know if the tell-tale signs produced by modern simple life couldn't be also produced by proto-life? Maybe they used some of the same processes without all the other stuff modern life does? Maybe life was bound to one location before it invented cells, and we just never checked that location? Maybe that location is now thousands meters below some ocean?

andrewflnr 7y ago

Possible answer: there was a hard takeoff in complexity between the first thing you can call life with a straight face and some minimal level of complexity you need to stay alive and spread in the real world. That minimal level of complexity characterizes the first organisms that show up in fossils. If it happened fast enough (maybe up to a couple million years, I dunno), there would be an infinitesimal amount of evidence that could easily be missed forever. If it only happened once, we would need to look at exactly the right rock, across the whole planet, with a microscope. Or it could already be recycled into the mantle. Ocean crust doesn't have a long lifespan, IIRC. Dunno about the rest, but I do think that rapid advancement from proto-life to something pretty sophisticated is likely, wherever it starts.

ajuc 7y ago

Do we even know what we're looking for? Maybe some expected geologic features are the fossils of the first life? How do we know if the tell-tale signs produced by modern simple life couldn't be also produced by proto-life? Maybe they used some of the same processes without all the other stuff modern life does? Maybe life was bound to one location before it invented cells, and we just never checked that location? Maybe that location is now thousands meters below some ocean?