Mass Extinctions

[JimC]

Depending upon your view of the term 'preordained'.

There is a pattern (behaviour of particles etc.), but it is so complex that we are incapable of working it out, and so we label it 'random', and then there's the possibility of 'probable futures' as opposed to 'set paths', with each being likely but with different values of probability...

Are you suggesting that the universe remains Newtonian and deterministic even as our understanding of quantum mechanics expands?

Actually, our understanding of Quantum so far asserts that we're determining history as we observe the present.

My understanding is that a Newtonian universe is deterministic and causal, thus, easily predicted. "Preordained" could exist in this sense without some kind of supernatural force ordaining events simply by following a cause-effect chain to it's conclusion. A quantum universe is probabilistic rather than deterministic because sometimes things (and by "things" I mostly mean "electrons") will exhibit behavior contrary to a deterministic chain. If something is not certain, it cannot be "preordained" in any sense of the word.

Actually, even a fully classical and Newtonian Universe would not have true clockwork predictability, due to the underlying chaotic nature of interactions between more than 2 bodies, even if only considering gravity.

Back to the OP, it is simply part of a debate that has been going on for some time, but many people seem to enjoy knocking down straw-men and opposing carictures...

Some palaeontologists view the effects of mass extinctions as having a greater effect on the present living assemblage than others. No one would seriously say it is the only factor, no one would say it is of trivial importance. And no sane biologist would say that the future shape of the tree of life is predictable in other than the most general terms - the academic debate is simply about whether it is worthwhile making some very general claims of recurring, statistical patterns in hindsight.