The origin of complicated polymers on the surface of an early ocean would have to include protection against the UV radiation that would have been present at the time. With no oxygen in the atmosphere there would have been high UV breaking down most molecules and polymers that floated unprotected on the surface. Although UV might have also served as a source for synthesis it would also caused breakdown of products. This seems like an excellent dynamic to research for the actual origin of homochiral ribose and polymers of RNA. This might have supplied molecules for the RNA world.

3 hours ago, Keith Chr said:

The origin of complicated polymers on the surface of an early ocean would have to include protection against the UV radiation that would have been present at the time. With no oxygen in the atmosphere there would have been high UV breaking down most molecules and polymers that floated unprotected on the surface. Although UV might have also served as a source for synthesis it would also caused breakdown of products. This seems like an excellent dynamic to research for the actual origin of homochiral ribose and polymers of RNA. This might have supplied molecules for the RNA world.

I was interested to learn of the protective, UV-absorbing properties of dissolved iron in the oceans before the Great Oxygenation Event. Fe II salts being more soluble than Fe III (less liable to precipitate as hydroxides) would have provided some protection in the photosynthetic zone. It also seems modern cyanobacteria contain scytonemin https://en.wikipedia.org/wiki/Scytonemin which acts as a UV-absorbing pigment. The evolution of this fairly early on would have helped.

There were a couple of threads on this some months ago, I think, if you are interested. One on lichens, if I remember right.