| ▲ | Qt45: A small polymerase ribozyme that can synthesize itself(science.org) |
| 62 points by ppnpm 5 hours ago | 10 comments |
| |
|
| ▲ | cyberax 4 hours ago | parent | next [-] |
| It's interesting, that we're getting down to the sizes of self-replicating RNA that realistically can form by a complete accident. Getting this sequence by random chance out of a pile of nucleotides is a 1 in 2^90 chance. That's around 1.2*10^27 or just around 20000 moles! Not at all an impossible number. |
| |
| ▲ | jjk166 3 hours ago | parent | next [-] | | 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 earth's oceans had nucleotide concentrations comparable to Bennu, then there would be about 10^39 nucleotides in the ocean. | | |
| ▲ | dekhn an hour ago | parent | next [-] | | 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. | |
| ▲ | nkrisc 2 hours ago | parent | prev [-] | | 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? |
| |
| ▲ | adgjlsfhk1 22 minutes ago | parent | prev | next [-] | | it's much more than 1 in 2^90. this specific 45 base sequence was found by random search which strongly implies that the odds of finding such a protein are much much higher (i.e. >2^-30) since the experiment probably only searched a couple million proteins | |
| ▲ | Paedor 2 hours ago | parent | prev [-] | | 20000 moles of length 45 nucleotides is 306 metric tons? Spread out over millions of years, that does seem completely feasible. |
|
|
| ▲ | java-man 5 hours ago | parent | prev | next [-] |
| 2009 paper: Self-sustained replication of an RNA enzyme [0]. [0] https://pubmed.ncbi.nlm.nih.gov/19131595/ |
| |
| ▲ | rcyeh 3 hours ago | parent [-] | | Amazing! The 2009 Lincoln & Joyce paper you cited catalyzes one bond per hour on average. (Doubling time = 1 hour, but only one bond between oligonucleotides needed to double.) OP's Gianni et al 2026 paper connects 45 nucleotides, taking 72 days (1700 hours) to yield 0.2%. The latter effort is like drawing the whole owl. That is incredible patience. Without access to the full article, I read only the abstract. I wonder if they used simulations to narrow the candidates? | | |
|
|
| ▲ | dekhn an hour ago | parent | prev [-] |
| See also: Spiegleman's Monster |
