Yes, the scientists, centuries scenario is a statement of faith on my behalf. Or more correctly hope. It certainly isn't a religion.
I also did mean organisms embodying the extant genetic code preempting organisms based on alternate coding chemistries. The first living cell was the first true von Neumann machine: it combined in one package the information and the tooling to replicate itself. That one complete cell was the revolution. It probably took a hundred million years or more for prebiotic assemblies to occur, accrete form and function, compete in their gentle nonliving way before thy yielded the first actual organism. It the took an eyeblink, perhaps a millennium, for that cell's descendants to fill every available environment, grazing on all the prebiotic assemblies.
If an alternate genochemistry was piecing itself together at the time, it lost the race. Once a living ecology was in place, the sheer invasiveness of life denied other life a chance to assemble itself.
On the off-chance that two distinct molecular scaffolds for encoding genetic information came into simultaneous being, they would be kinetically distinct. The faster, fitter scheme would win very quickly and completely.
cheers js |
