A quote from the abstract of the paper linked in (a)
A polymer longer than 40–100 nucleotides is necessary to expect a self-replicating activity, but the formation of such a long polymer having a correct nucleotide sequence by random reactions seems statistically unlikely.
Lets say that no string of nucleotides of length < 1000 could self replicate. And that 10% of nucleotide strings of length >2000 could. Life would form readily.
The “seems unlikely” appears to come from the assumption that correct nucleotide sequences are very rare.
What evidence do we have about what proportion of nucleotide sequences can self replicate?
Well it is rare enough that it hasn’t happened in a jar of chemicals over a weekend. It happened at least once on earth, although there are anthropic selection effects ascociated with that. The great filter could be something else. It seems to have only happened once on earth, although one could have beaten the others in Darwinian selection.
We can estimate apriori probability that some sequence will work at all by taking a random working protein and comparing its with all other possible strings of the same length. I think this probability will be very small.
I that this probability is small, but I am claiming it could be 1 in a trillion small, not 1 in 10^50 small.
How do you intend to test 10^30 protiens for self replication ability? The best we can do is to mix up a vat of random protiens, and leave it in suitable conditions to see if something replicates. Then sample the vat to see if its full of self replicators. Our vat has less mass, and exists for less time, than the surface of prebiotic earth. (Assuming near present levels of resources, some K3 civ might well try planetary scale biology experiments) So there is a range of probabilities where we won’t see abiogenisis in a vat, but it is likely to happen on a planet.
We can make a test on computer viruses. What is the probability that a random code will be self-replicating program? 10^50 probability is not that extraordinary—it is just a probability of around 150 bits of code being on right places.
A quote from the abstract of the paper linked in (a)
Lets say that no string of nucleotides of length < 1000 could self replicate. And that 10% of nucleotide strings of length >2000 could. Life would form readily.
The “seems unlikely” appears to come from the assumption that correct nucleotide sequences are very rare.
What evidence do we have about what proportion of nucleotide sequences can self replicate?
Well it is rare enough that it hasn’t happened in a jar of chemicals over a weekend. It happened at least once on earth, although there are anthropic selection effects ascociated with that. The great filter could be something else. It seems to have only happened once on earth, although one could have beaten the others in Darwinian selection.
We can estimate apriori probability that some sequence will work at all by taking a random working protein and comparing its with all other possible strings of the same length. I think this probability will be very small.
I that this probability is small, but I am claiming it could be 1 in a trillion small, not 1 in 10^50 small.
How do you intend to test 10^30 protiens for self replication ability? The best we can do is to mix up a vat of random protiens, and leave it in suitable conditions to see if something replicates. Then sample the vat to see if its full of self replicators. Our vat has less mass, and exists for less time, than the surface of prebiotic earth. (Assuming near present levels of resources, some K3 civ might well try planetary scale biology experiments) So there is a range of probabilities where we won’t see abiogenisis in a vat, but it is likely to happen on a planet.
We can make a test on computer viruses. What is the probability that a random code will be self-replicating program? 10^50 probability is not that extraordinary—it is just a probability of around 150 bits of code being on right places.