Actually, I perpetrated a well-accepted myth in Part 1. The atmosphere could not be all methane before photosynthesis, there had to be a lot of co2, otherwise no oxygen. Whoops, I must add a footnote.
*The Galactic Seeders are something I came up with to define the jump from organic soup to DNA. We await the coming of the quantum computer DARWIN2 to figure out the evolution of soup.
And don't go after me about the Sun being 20% dimmer. We aren't talking percentages here, the uncertainties are greater than a factor of 10. But not temperature, that's solid shirt-sleeves forever.
Even those giant mats of bacteria sucked up carbon, and new guys on the block sucked up all the co2 until we got 20% oxygen. Ever wonder why we don't have more oxygen? It's a poison.
Enzymes responsible for nitrogenase action are very susceptible to destruction by oxygen. For this reason, many bacteria cease production of the enzyme in the presence of oxygen. Many nitrogen-fixing organisms exist only in anaerobic conditions, respiring to draw down oxygen levels, or binding the oxygen with a protein such as leghemoglobin.
Obviously, photosynthesis is happy with 0% O2 because that's how it started. But get up to that 20% and things begin to happen. We animals love it, but we are ticks on the giant plant and bacteria elephant.
Now, the weird thing is that plants need co2 to grow, yet they are dedicated to wiping it out. Thus co2 is the 'limiting factor' on growth if you have plenty of water. This proven by the fact that I add co2 to my planted aquarium, and they add it to greenhouses. Where did they get it before we animals started burning things and breathing. Do plants really care about us?
- blah blah continued blah blah