Four Ideas from The Origin of Life Symposia

From Lucy M. Ziurys, professor of astronomy and chemistry, University of Arizona.
1) There is an incredible amount of interesting organic chemistry happening n the vacuum of space.
2) When the earth formed, it is likely that it had no carbon. Over its lifetime, the earth acquired carbon from asteroids, comets, meteorites and cosmic dust.

From David Catling, European Union Marie Curie Chair, University of Bristol.
3) It is now believed that most of the earth's water did not come from asteroids. Why? The deuterium/hydrogen ratio in the ocean does not match the ratio found in asteroids. We are no longer sure where the planet's water came from.
4) If we take all the reductive potential stored in carbon-carbon and carbon-hydrogen bonds, there isn't enough of these types of molecules to account for all the oxidative potential on earth, stored as molecular oxygen in the atmosphere. So it seems unlikely that photosynthetic activity caused the great oxidation of the earth's atmosphere all on it's own. Apparently our pre-oxygenated atmosphere was hemorrhaging methane and the lost a whole lot of reductive power. I'm not sure how widely accepted this theory is. But we know that about 3 billion years ago a change in the atmosphere coincided roughly with the appearance of photosynthesis. So what's up with that? Was an oxygenated environment essential for the development of photosynthesis? That's turning the whole theory on its head. What do you think?

Link to the symposia website. Also, the talks were recorded, I'll let you know if they become available online.