That is the odd thing about the history of life on Earth isn't it? Prokaryote popped up almost as soon as was conceivably possible. And then. Nothing. For billions of years. The plausible explanation is that you need Oxygen for Eukaryotes and that's how long it to change the chemistry of a planet. It just seems weird to me.
"Let me make my position clear. The miracle, and I do not mean it in the religion sense, I mean it in the evolutionary sense, the miracle of the evolution, is the cell. While there are theories involving an RNA world and selforganising, it remains a mystery. Once you had the eukaryotic cell from the point of view of evolution and development it was downhill all the way, very very easy. "
