Different in degree or kind: Egnor's take; more on gaps (Introduction)

by dhw, Monday, October 17, 2016, 12:46 (2747 days ago) @ David Turell

dhw: The reference to pre-adaptation becomes very clear once we realize that there have been so many instances of fish venturing out onto dry land, and being able to cope with the problems of movement and of breathing. Fish that live at the bottom of the sea or lake have fins that are “limb-like already”. We are not even talking of innovations here but of adaptations.
DAVID: Yes, comparatively the anatomy is similar but the fin function is different, although there are walking fish I've mentioned. But they stay fish! And of the instances of brief on land excursions, all but one all stayed fish. That is the proper interpretation of this article. And where did the primitive lung come from while still in the water? That is a key point. The authors are Darwinists who are trying to make it sound easy.

The authors acknowledge the mystery of the fifth type that did not stay fish and led to us. As regards primitive lungs, they drew attention to conditions in which water lost oxygen and air proved a better option, and there were different families of fish that spent days on land. It would be interesting to google the history and different forms of primitive lungs, but I’m afraid I don’t have time.

Dhw: We are left with the information that many water-based organisms have made the transition, and crucially the article makes it abundantly clear that the move was made for environmental reasons.
DAVID: Transient transitions only. Environmental stresses, yes.

Again, this is such a logical process that one really can’t dismiss the idea that it
was the starting-point for the all-important permanent switch from water to land.

dhw: Any “pre-adaptations” would have taken place for those same reasons: loss of oxygen, moving along the seabed, habitat alternating between wet and dry, or drying up altogether. The pattern is clear: need gives rise to change. It’s not change in preparation for need.
DAVID: Agreed. At times of demonstrated need, organisms adapt. ..But I still see no need for human brain enlargement. Their ape forbears did just fine until the humans crowded the Earth.

As we have said over and over again, there was no need for any advance beyond bacteria. Hence, my hypothesis that evolution progresses through a (perhaps God-given) drive not only for survival but also for improvement. In the case of humans, somewhere along the line, pre-humans developed an enhanced consciousness of the world around them. The source of consciousness generally remains the great barrier to all of our hypotheses. But in the context of your dualism (see the sapiens thread), for this awareness to be of any use, our pre-sapiens ancestors needed a larger brain to improve means of expression and of materially carrying out the instructions issued by consciousness. Hence the need gives rise to physical change, as opposed to physical change creating the need.