It isn't quoted from anyone else or revised. It was quoted directly from you! FR quoted directly from you as well!

But let me answer your question, or rather, I shall attempt to rephrase it in such a way as to be reasonably intelligible. If I have misunderstood, please tell me!

How is it that evolution theorises slow changes but catastrophes (punctuated evolution) need big ones?

In fact you see both. There are many examples of slow changes over time in things such as invertebrates, molluscs, plants, etc. But there are also big changes, where nature seems to "experiment" - after extinction events. Where do these big mutations suddenly come from? Stress.

Have you heard of hypermutation? Where segments of DNA sequence are deliberately shifted around by the organism to create changes? That's one possible mechanism. Another is that creatures under stress are more likely to have mutations. But changes in the DNA don't stop even in animals that don't seem to have changed physically for millions of years. Mutations accumulate in the DNA over time (that's how the idea of "molecular clocks" works) - even if these do not appear as physical changes. If an organism is adapted to it's surroundings, it can reach some sort of an equilibrium state. Only a change in the environment or population will allow changes to manifest themselves.



I didn't doubt you over the lizards - for instance I know that crocodile young have their sex determined by the temperature of the eggs during incubation. However, I fail to see how reptillian examples can have any meaning in a discussion of human evolution, as that was how the question was phrased.

But thanks all the same - it was interesting. You learn something new every day, as my mother always says. I try to.
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Only two things are infinite, the universe and human stupidity, and I'm not sure about the former. -
Albert Einstein