Miscellany (General)

by dhw, Monday, January 11, 2021, 10:40 (579 days ago) @ David Turell

Cambrian Explosion

dhw: I don’t know why you have added “suddenly” when you agree that there is no “abrupt dividing line in evolution”, and you have ignored my point that 55 million years does not constitute “suddenly”...

DAVID: The 'suddenly' applies in the Cambrian in terms of complexity. After the initial slope, the next animals are enormously complex compared to the few fossils on the slope.

dhw: Agreed, but my point is that 55 million years is a long time, especially if we embrace the concept of cellular intelligence responding to new conditions and opportunities.

DAVID: I don't see how cellular intelligence adds anything when the subsequent gap in complexity is so large. From Dawkins: " With regard to the sudden explosion of new body plans in the Cambrian, even Richard Dawkins admitted, "It is as though the fossils were planted there without any evolutionary history.'"

Maybe he wrote that before the new discoveries of pre-Cambrian links.In any case, it does not invalidate my argument. See below for the difference cellular intelligence makes.

DAVID: And: the pervasive patterns of natural history are analogous to the historical patterns found in modern technologies: new designs appear suddenly followed by variations on the pre-existing themes. […] It is only logical that the far, far more advanced nanotechnologies found in biology are also examples of progressive creation.

Of course it’s progressive creation! Evolution is the history of innovations and variations on pre-existing themes! Nobody can explain the innovations, which is why we theorize. 55 million years is a huge expanse of time. But regardless of time, some of us doubt that random mutations would explain the complexities. Cellular intelligence, responding to the demands and opportunities arising out of new conditions, makes all the difference by eliminating chance as the driving force. But it's a theory, not a proven fact.


DAVID: God does what God does. We usually figure out why after more research.

dhw: If God exists, no one will argue with your first sentence. Your second is on a par with Dawkins: “...if there is something that appears to lie beyond the natural world as it is now imperfectly understood, we hope eventually to understand it and embrace it within the natural.” (The God Delusion, p. 14). You simply hope to embrace it within the divine. And both of you regard yourselves as scientists!

DAVID: You are ignoring the history of science. After time we usually figure it out. Here I know Dawkins is correct.

dhw: There is a huge difference between a prophecy and a belief! And there is an equally huge difference between “eventually science will figure it out” and “eventually science will confirm my belief that there is/isn’t a God”. Both of you claim that science is already the basis of your diametrically opposed conclusions! In your case, you also prophesy that science will vindicate your theory concerning how and why your God created life. You and Dawkins can both believe what you like, but your respective utterances of faith have nothing to do with science.

DAVID: Science offers the only evidence we have. Remember!

That is what I would say to you and Dawkins. Your faith that science will confirm your respective beliefs is totally unscientific. One should wait till science has provided the evidence before shouting down those who do not share your faith.


dhw: Although this is adaptation and not speciation, it emphasizes the crucial link between cellular change and current conditions. The body size increases in response to the warmer climate – not in anticipation of it!

DAVID: Only in known species adaptations. You haven't explained speciation.

That is what I have just said (bolded)! But both processes involve cellular change, and since we KNOW that cell communities respond to environmental change, it is perfectly feasible that speciation followed the same pattern. What evidence do you have that cell communities change IN ANTICIPATION of changing conditions?

DAVID: It shows not all species are driven to change. Hominins changed and the environmental evidence is not strong as a reason to arrive at us.

dhw: When conditions change, some species survive intact, some adapt, some die out, and some change into new species. Nobody knows for sure, but there is no reason to suppose that this general pattern did not apply to hominins and humans.

DAVID: It doesn't explain our unusual brains, and you know it.

dhw: Sorry, but I think it does, and our long discussion on “brain expansion” covered all aspects of this explanation, which I’m reluctant to go through again. But nobody “knows” how speciation or brain expansion occurred – we can only theorize.

DAVID: Yes we theorize and our brains are not explained by environmental drive. The apes proved that long ago.

I'd hoped you would not re-open the “brain expansion” thread. We've been over this umpteen times. It is perfectly feasible that local conditions made it necessary or advantageous for particular groups of apes to descend from the trees. It is perfectly feasible that a change of environment would have resulted in changes to the brain, as it learned to solve new problems. We KNOW that the brain changes when it accomplishes new tasks. Remember?

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