7 ms·

Not the GP but maybe I can help elucidate the position they're representing. The GP advocates for what is known as the "metabolism-first" hypothesis in origins

Not the GP but maybe I can help elucidate the position they're representing. The GP advocates for what is known as the "metabolism-first" hypothesis in origins of life theory. The motivation of this theory that some chemists and biologists find it implausible that a self-catalyzing RNA based biological machinery would have formed spontaneously from a collection of basic precursor chemicals, even given very long spans of time and large volumes of precursors. They believe this because nucleic acids are very complex structures and themselves require very complex biologic machinery to assemble, and their understanding of the likelihood of chemical reactions suggests its unreasonable to expect them to form in geological time spans. They posit that instead its more likely that nucleic acid based systems were themselves preceded by system(s) composed of sets of simpler chemicals (ones which are likely to form spontaneously) which together catalyze each other's formation (a so-called "auto-catalytic set"), and that this era of simple metabolisms eventually produced a nucleic acid based system which completely overtook and replaced/assimilated the more primitive auto-catalytic set world. Here's a primer on the metabolism-first hypothesis: https://www.statedclearly.com/videos/what-is-the-metabolism-first-hypothesis-for-the-origin-of-life/ https://www.statedclearly.com/videos/what-is-the-metabolism-...

Ultimatt 4y ago
RNA first is about stored heritable genetic information? At least I've not met anyone who's in some hardline way RNA miraculously appears and starts creating the auto catalytic networks second. How does the RNA appear? Slowly at random from nothing? Why would anyone think this, it doesn't pass thought experiment level parsimony. The reason to highlight RNA first is because if you just looked at whats alive now you might assume DNA is the older molecule in use as its the primary store of genetic information for most things alive right now. The big idea is that it wasn't. That doesn't mean everyone means its the first molecule to exist in the history of molecular life...
- popcube 4y ago
  because RNA is used in more old clade of tree of life. DNA is a younger character in history
ramraj07 4y ago
Thanks for the reference. As the other commenter mentioned, this is great research but I don’t see it as with odds with a molecule of RNA being the first living thing ever. We didn’t discuss before what powered these RNA molecules, but clearly this research is showing us one aspect of it (preexisting metabolic pathway like reactions). These systems might be considered as evolving the same way the sun is evolving I suppose? In the end I would classify life as something that has encoded information on how to create itself and the machinery to do it (or at least the means to recruit the machinery and raw materials) and actually propagate itself perpetually in the right conditions. RNA is still the only viable candidate for that.

Ultimatt 4y ago

RNA first is about stored heritable genetic information? At least I've not met anyone who's in some hardline way RNA miraculously appears and starts creating the auto catalytic networks second. How does the RNA appear? Slowly at random from nothing? Why would anyone think this, it doesn't pass thought experiment level parsimony. The reason to highlight RNA first is because if you just looked at whats alive now you might assume DNA is the older molecule in use as its the primary store of genetic information for most things alive right now. The big idea is that it wasn't. That doesn't mean everyone means its the first molecule to exist in the history of molecular life...

popcube 4y ago
because RNA is used in more old clade of tree of life. DNA is a younger character in history

ramraj07 4y ago

Thanks for the reference. As the other commenter mentioned, this is great research but I don’t see it as with odds with a molecule of RNA being the first living thing ever. We didn’t discuss before what powered these RNA molecules, but clearly this research is showing us one aspect of it (preexisting metabolic pathway like reactions). These systems might be considered as evolving the same way the sun is evolving I suppose? In the end I would classify life as something that has encoded information on how to create itself and the machinery to do it (or at least the means to recruit the machinery and raw materials) and actually propagate itself perpetually in the right conditions. RNA is still the only viable candidate for that.