Precambrian environment (Introduction)

by David Turell , Tuesday, October 29, 2013, 21:46 (4020 days ago) @ dhw

dhw: A rise of up to 10% would be substantial enough to make a difference. But I really don't trust measurements of this kind. You can't help thinking that in a thousand years' time ... or even 100 ... all the calculations will be different.-Again they were using isotopes with known half-lifes. Fairly trustworthy if you beliieve scientists.
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> dhw: They cannot say how much, but there was PROBABLY ample...If you don't read these articles carefully enough, you come up with conclusions like: "There was lots of oxygen...".-Oxygen has been all over the place in concentration. at one point as high as 25% which resulted in huge forest fires, as shown by ash levels at the layer of that time in history. -> 
> dhw: I find this very interesting. "A way of life that tried to evolve into a multicellular life form...", "...microbes that experimented with a way to evolve into some form of multicellular existence..." Margulis's concept of evolution proceeding through cooperation continues to gain ground.-With whom? This is just stream of consciousness writing, no substance in fact.
> dhw: But what cooperates? These appear to be cells trying to merge. According to David, they were automatons obeying God's built-in instructions. I'd like to know more about these strange fossils. "Microbes experimenting" doesn't sound like automatons obeying instructions, but I guess different scientists have different interpretations.....-We do know what we don't know: how evolution really works.