Due the constant radiation, some of the prokaryotic cells degenrate, losing some of their RNA-Code. They are now not able to live alone, so they start to "infect" healthy prokaryotic cells with their broken code, forcing them to produce more of these broken cells.
I'm not sure if I should congratulate you or not, but you made the first virus-like organisms. Although viruses aren't considered "life" in our world, in this one, they should be. Sort of.
Prokaryote does not imply RNA.
"I'm going a bit out of my domain again, okay?"
Spur the evolution of DNA and proteins in the black smoker microbes.
Your cells eventually start using DNA, a double helix of RNA with some other extra differences. How far we went from those bubbles of lipids with a bit of RNA in them! Not that far... Yet. Overall, DNA is a more stable storage for genetic information, eventually all the deep sea cells adopt this method. The DNA cells outbreed the more primitive RNA cells. RNA-using prokaryotes are extinct down there.
The next step: The invention of cillia and advent of real predators who seek out prey! Amoeba armada rise up!
Amoeba? No... Not yet. They are like a 100 times more complicated than the simple lipid vessels of RNA/DNA we have now.
The current prokaryotes are either amoeba or just go with the flow of the water...
Prokaryotes are basically just naked nuclei. Vessels for RNA/DNA. They have yet to develop another membrane and organelles, like amoeba, which are eukaryotes.
"true" amoeba are eukaryots, just saying.
Also the free radicals come from O2 respiration, not photosynthesis. And a single enzym, degrading H2O2 into H2O and O2, resolve the problem quite well. Otherwise, just dump it out. For small primitive bacteria it should be fairly simple (eukaryots are 10 times bigger and have their free radicals produced deep inside, while bacterias have them on the external membrane.
Photosynthesis will cause free radicals as well as O2 respiration.AFAIK. However, the problem still remains that photosynthesis is impossible without compertamentalization.
Anyway, my action. As a side effect from the now persistent virusses amongst the Deep creatures, other things started to happen. Even adult/ healthy cells started to temporaliy merge with each other, periodically sharing genetic information before parting again.
Whoa, big step forward. Sexual (well, sort of) reproduction! This really will spur evolution on!
However, the problem still remains that photosynthesis is impossible without compertamentalization.
http://en.wikipedia.org/wiki/Cyanobacteria
I'll leave this here and watch.
Hmm, if you really want to evolve cyanobacteria from one of the current prokaryote branches and then maybe evolve them into chloroplasts, it's up to you. But you're going to wipe out most of the anaerobic organisms here. Like on Earth, this will be one of the biggest revolutions of the composition of life ever.
The chloroplasts and mitochandria, they are supposed to be the remains of ingested cells. Is this required? I always wondered why the offspring of cells who incorperated those components didnt eat them and start anew...
Well, maybe the cells "decided" to keep them around, because it's much more efficient for them. Mitochondria and chloroplasts act like their own organisms inside the cells, they divide up independently, they even have their own DNA.
Bokecca the god of righteousness and persistence commands the primordial soup and black smokers to drive the comet invaders from the world! Maybe introducing some stimuli to promote mobility would be a good start...
Alright, we seem to have the first conflict of divine interests here. For no apparent reason... Ah well, doesn't matter. Cells from the comet(s) have already populated most of the world oceans and they coexist. It'll be hard to drive them extinct. The deep sea black smoker organisms won't be able to help your interests, as they only populate underwater zones with volcanic activity.
As you can surely figure out, the little cross means that the species is extinct.