Natures wonders: walking fish have not evolved (Introduction)

by David Turell , Monday, January 27, 2020, 18:16 (1760 days ago) @ dhw

DAVID: You are misusing the word 'trigger', which has extended this discussion. A trigger causes something, as in a gun firing a bullet. A trigger is a direct cause or precipitater of action. The nuance is that environmental change allows for new possibilities or demands them if threatening, but is never a direct cause, as you imply regarding the Cambrian. The cause of a new species has to reside in that species, which is why I have God dabbling, since I don't think existing species can do it.

dhw: Then let me clarify: by “trigger” I mean that the environmental change begins the process (David’s bold) of organismal change, which is a REACTION to the new conditions. I do not believe organisms change (or your God changes them) in anticipation of new conditions. What “resides” in species is the ability to RESPOND to new conditions by changing their structure, i.e. adapting and/or innovating. You asked why changes might take place even if there is no danger. I have given you an answer: improving chances of survival. I don’t know why you can’t accept that.(Newly bolded by dhw)

DAVID: You are still struggling. Note the bold. An environmental change may invite change in organisms or adaptation, but no response is required as shown by the ancient scorpion fossils from 437 mya that show virtually no change until now. (Saturday, January 18, 2020, 20:15).

dhw: Of course it’s not required if the organism can already cope! We are not trying to explain why organisms remain the same! We are trying to explain why they do change when they change! Proposal: some must change if they are to survive; others may make use of new conditions to improve their chances of survival. Hence both adaptation and innovation. Why do you object to this?

The bold is your problem. It is not the threatened ones that are at issue (see my statements above), it is the ones that that are changed for no good reason. Whatr pushes them, if anything? God, yes!

DAVID: Dangers to survival may cause extinction (Raup) or the proper response to continue on. We know epigenetics allows minor adaptations, nothing more, so how species evolve is still totally unknown to science.

And that is why we have different theories: e.g. one that organisms do their own designing, and one that your God does it all.

DAVID: If there is no present danger, there is no reason for changes to appear in advance of survival requirements. Your final statement implies organisms can foresee troubles ahead since you think they can speciate on their own. Really? I certainly don't accept it. 'Improving chances for survival' is pure Darwin-speak, bringing up the old saw of survival of the fittest.

dhw: I keep telling you that my theory does NOT involve advance changes or foreseeing trouble ahead. I’ve bolded it for you, and next time I’ll capitalize it AND bold it. It is you who have your God gazing into a crystal ball, foreseeing trouble (or possibly organizing it himself). I know you don’t accept the theory of “natural genetic engineering” by which cells may do their own designing, but please stop pretending that this involves advance planning. Yes, “survival” is Darwin-speak. Do you honestly think organisms are not motivated by the drive for survival?

Wow! Don't you realize 'motivation' requires a thinking mind?