Natures wonders: walking fish have not evolved (Introduction)

by dhw, Saturday, January 25, 2020, 11:10 (1762 days ago) @ David Turell

DAVID: My usual answer: environmental change if not uncomfortable or dangerous (Raup) doesn't cause anything to happen to advance evolutionary adaptations. We do not know what causes animals to make new species if there are no pressures, since they are not required to change.

dhw: You persistently ignore the second point, which I have now bolded for you. If a different environment offers better opportunities for survival (e.g. water instead of land or, to follow one theory relating to the Cambrian, an increase in oxygen levels), this could trigger innovation. But of course nobody knows what causes speciation, and that is why we have different theories.

DAVID: I have answered: you have made my point. No one knows what triggers innovation, and any change in environment does not mean it must happen, unless it is a dangerous change requiring protective mutations. Offering opportunity is a neat subterfuge statement. Changes or advances can also be spontaneous for no obvious reason.

There is no subterfuge. and nobody said it MUST happen! I am pointing out that environmental change is a trigger not only for adaptation but also possibly for innovation. If, for some reason, a new mass of water appears, it may be that some bold creature reckons it will find more food in than out, so into the water it goes, and its body may undergo such radical changes that we then have a new species. Some experts think an increase in oxygen triggered the Cambrian Explosion. Maybe the extra oxygen allowed existing creatures to do things that had never been done before, and the body changed accordingly. We don’t know, but I have given you a possible answer to your question why changes might take place even if there is no danger.

DAVID: Your view of God thinks He wanted to set everything up and just watch, with no further participation, a sort of a Deist view.

dhw: Do I really need to keep repeating that your God may have done the implanting? I don’t have a fixed view of God, but yes, Deism is one possible view that fits in perfectly with the history of life. Even you have told us that your God is hidden. Do you have any logical grounds for rejecting the Deist theory?

DAVID: To be honest, yes. I assume if He did all that creating He'd like to follow the results and as I view God as supremely purposeful, it is most likely He is still actively interested in what He produced. To do it and leave seems odd.

dhw: He might be watching the show unfold, but not wishing to interfere. Not logical?

DAVID: We don't know that do we? Humanly logical, yes.

We don't "know" anything! But what other logic can you apply? If you mean watching a show is human, how about this: “I agree He probably does have some of our attributes” (D.Turell) to reinforce: He “very well could think like us” (D. Turell).