The pay wall doesn't permit much access to the details of this. A better summary is available at the UK's MRC website, link below.
https://mrclmb.ac.uk/news-events/articles/bridging-the-gap-f...
Qt45: A small polymerase ribozyme that can synthesize itself
21–23 of 23 posts
Re: Qt45: A small polymerase ribozyme that can synthesize itself
#22Earlier quoted context omitted.
Note that the Bennu asteroid sample had approximately 5 nanomoles of nucleotides per gram, meaning 20,000 moles of nucleotides could be delivered by a single 4 million ton asteroid, which if it were a spherical carbonaceous chondrite would be about 183 meters in diameter. An asteroid about that size impacts earth roughly every 36,000 years, and that mass of meteor material falls to earth each century. If primordial e…
If raw materials isn’t the bottle neck for life every where, then what might it further down the line between oceans full of nucleotides and life? The oceans themselves?
Temperature range and magnetic field are my first thoughts.
Re: Qt45: A small polymerase ribozyme that can synthesize itself
#23Earlier quoted context omitted.
Note that the Bennu asteroid sample had approximately 5 nanomoles of nucleotides per gram, meaning 20,000 moles of nucleotides could be delivered by a single 4 million ton asteroid, which if it were a spherical carbonaceous chondrite would be about 183 meters in diameter. An asteroid about that size impacts earth roughly every 36,000 years, and that mass of meteor material falls to earth each century. If primordial e…
I don't see any reason for the source molecules to come from space. We already know that nucleotides will spontaneously form and polymerize in conditions consistent with the early earth, and a meteorite origin just moves the source of those nucleotides elsewhere but doesn't answer how they formed.
Delivery by meteorites isn't necessarily the only or even primary source, but the fact is that it is a source we can directly observe, and it is a sufficient source. Earth's primordial chemistry likely did create more, but the existence of those conditions is theoretical, and such additional production need not be invoked to explain the needed level of abundance. Even a world with very different conditions from primordial Earth would likewise receive vast quantities of nucleotide during its formation and continuous replenishment afterwards.