[jlogajan]

Does timing agree with any major extinction event?

If there was life before 3.9 billion years, there is no remaining evidence of it. I believe life as we know it didn't appear for another 400 million years or so, far as we can tell. Life forms were very simple for a very long time, single cellular guys for over 2 billion years. The interesting multicellular stuff didn't start until about 500 million years ago. There were occasional mass extinctions during those last 500 million years.

[lwoodham]

Any way to tell when the genetic defect first occured which eventually led to the deviant human race known as Democrats?