You really don’t seem to understand how enzymes work, I’m afraid. Organisms mix and match bits of enzymes all the time, evolutionarily speaking. They’re modular, and it’s a simple matter to rearrange the modules. As I’ve said, the experiments have been done in the lab to show that it can be done with synthases. Thermodynamically, the only functional difference between the enzymes is the arrangement of the anticodon recognition sequence, and the energy differences between them is negligably tiny. There’s so reason to think that there’s a significant energy minimum here that necessarily links a specific codon to a specific amino acid. If nothing else, those two regions of the enzyme are so far apart that they can’t really be seen as interacting in any meaningful way.
Just to show the size of the numbers a bit more.
According to an online calculator I found, 21^64 = 4.1*10^83. So it’s a lot bigger than I thought. Maybe you math-types can check. And according to How many atoms are there on earth? - Answers, there are estimated to be only something like 1.3e50 atoms that make up the earth.
So if every atom on earth was a triplet codon, and the Earth was 10 billion years old, and each atom goes through a state every second (seconds/year=3*10^7), that gets you to 10^67. Still much much smaller than 10^83. But of course, bacterial generations are typically longer than a second, and even if they were they wouldn’t change their genetic code every generation, and the entire mass of the earth isn’t made of triplet codons.
So even if there were one and only one thermodynamically optimum genetic code, there’s no way it could be discovered simply by trying all combinations.
If they really are that modular then I don’t see any way around a single “ancestor”. I still wont accept that this is all the result of a single abiogenic event, but at some point the various systems must have coalesced into one system out of many possible ones.
It’s true, I don’t know biochemistry. Is it possible though, that the process could work the way the chirality problem does. Since it is autocatalytic, then the process feeds itself into defining the dominant system before what we would call life even develops. In that sense, there would still be multiple ancestors.
I’ve never heard of nanobes or nanobacteria. I just read both the nanobacterium article and the nanobe article on Wikipedia and it appears to me there’s not much consensus that these things represent some form of life or even show any life-like activity. In fact, it’s not solidly persuasive that they even exist. I think we can safely say that we don’t know enough about these possible structures to base any kind of argument at all on them.
I think I see what you’re getting at. I’ll need to chew it over to come up with a way to express my reaction.
I agree that it is perfectly plausible that there could have been multiple types of replicators that contributed to what became life. It seems perfectly plausible to me that at least RNA proto-life and membrane protolife incorporated each other.
And it certainly is possible that there were many, or even hundreds, or even billions of different genetic codes at the very beginning of life, but one form out competed and swamped all the others. I don’t think anyone insists that there couldn’t have been multiple instances of biogenesis, only that all extant life on earth is the product of only one instance of biogenesis, with the understanding that “one instance” has to be taken broadly.