Miscellany (General)

by dhw, Wednesday, May 12, 2021, 10:58 (1289 days ago) @ David Turell

BATS
dhw: I am asking why you, who believe in common descent, think it’s impossible for bats to have had an ancestor, and why you should take it for granted that every stage of speciation, going back hundreds or even thousands of millions of years, should have left us with a complete fossil record of itself.

DAVID: Incompleteness is a hopeful position after hundreds of years of searching for fossils.

dhw: No more hopeful than the belief that there is a God who decided one day not to use existing species as the basis for new species, but to specially design the bat de novo, even though his one and only purpose was to specially design H. sapiens. You see how difficult it is to accept your arguments in the light of your combined beliefs? And I would still ask if you honestly believe it is possible to have a complete fossil record of every life form for the last 3 thousand million years.

DAVID: It certainly looks as if God designed Cambrians de novo. And I'm sure we will never find a fossil for every past life form, but enough, as now, to see reasonable series of changing forms with huge gaps in forms as in the whale series.

So once your God had operated on the pre-whales to change their flippers to legs before they entered the water, do you think that over the centuries he kept popping in to do a fiddle here and a twiddle there, until he finally got the whale he wanted? Ditto with all the hominins and homos? Ah, but let us remember: you have no idea why he evolved sapiens in this way. Or presumably whales.

Seals
dhw: The article contains no reference to random mutations, so I don’t know why you tried to dismiss it as “typical Darwin think”, or why you objected to the statement that adaptation to new environments helps us to understand diversity.

DAVID: I view it as an empty observation.

dhw: Certainly no emptier than your dismissal of it as “typical Darwin think” when it never even mentions the “Darwin think” you objected to (random mutations). And in fact I would say the interaction between adaptation, innovation and the environment is of prime importance to our understanding of evolution.

DAVID: My understanding of evolutionary gaps is there must be a designer.

I thought we were discussing the non-mention of random mutations and the importance of interaction between organism and environment. But even this comment of yours raises the problem of common descent, which you claim to believe in. No wonder you have no idea why your God chose to evolve H. sapiens, since you now appear to be a full-blooded Creationist.

The obstetric dilemma
DAVID: Yes. Your paragraph is wishful thinking. The pelvic required changes had to result from massive coordinated mutations.

dhw: Do you really believe that all Lucy-mothers survived childbirth in those early days? That’s what I would call wishful thinking. Yes, the pelvis required major adaptations to accommodate the larger heads, just as the pre-whale required major adaptations to adapt to marine life. But in both cases, I suggest there would have been a clear sequence: new conditions led to appropriate responses. It happens all the time.

DAVID: Thanks to a designer anticipating the needed changes. More wishful theorizing.

The idea of a designer operating on pelvises before the big-brain baby is conceived, or of transforming pre-whale legs into flippers before the animal enters the water, does indeed smack of wishful thinking!

DAVID: I would say every mother died unless her pelvis was changed to a bigger size. Or each fetus was dragged out with a crushed skull. Having delivered a bunch of kids in my training, I can tell you almost all newborns have slightly molded heads on arrival which revert to normal shape quickly. That is how tight the current setup is. Early homo kids had to have the room to get out. It is still a dilemma: Dad's DNA, Mom's DNA and kid's DNA all had to cooperate. You can't wish that problem away in finding a natural solution. It has to be designed.

I would say every mother would have died if some pelvises hadn’t allowed some bigger-brained babies to get out. The species survived. If your God had operated on every individual pregnant Lucy-mum before she became pregnant, you’d have thought there would have been no deaths and no problems at all, but even in our own times, it’s a struggle. Why do you think your God made it so difficult and so painful each time he popped in to perform his pelvis-expansion operation? And why do you think cooperation has to be simultaneous? I propose that problems arise before solutions are found. In this case, the enlarged brain was the problem which the pelvis had to solve.

Ancient ape fossils need more study
QUOTE: "In other words, fossil apes are essential to reconstruct the 'starting point' from which humans and chimpanzees evolved.'"

You can say this about the whole of evolution. Fossil everything is essential to reconstruct how speciation of all kinds took place. I don’t think there’s much chance of that, but some folk like to talk of gaps as if they really expect each set of dead bodies to hang around forever.