Charles Darwin

What I am primarily interested in is science, and in this instance, how it bears on evolution. Whether that makes evolutionists look good or not is not my concern. I'm sorry if I've given any impression otherwise. In any case, yes, I'd be interested you hear your assessment of the mathematical challenge. Again, my interest was in the circular response that they received, which, if memory serves, you will find in that same volume.

Ken

Speaking for myself, in my move from old-earth creationism to divinely guided evolution and then to naturalistic evolution roughly three years ago, it was not primarily the kinds of considerations you attribute to evolutionists that led me to my current perspective. Yes, the apparent sub-optimality and "nastiness" of many aspects of nature did play a small part, but I had previously as a creationist been fully aware that this planet is far from Edenic, and my faith had ways of accommodating this fact.

What convinced me that common descent was inescapable was its explanatory power. When comparing special creation with common descent, the latter neatly explained too many phenomena that the former could only take ad-hoc stabs at. Certainly, an all-powerful Intelligent Designer could do anything s/he/it decided to do, e.g., give five fingers to a dolphin and amorphous cartilage to a shark for much the same function. Or give humans sparse body hair that rises on end in the face of cold or fear, just as apes have fur that stands out to insulate from cold or make the body appear larger when threatened. Or place apparent tooth-making genes in modern birds. Or cause additional lateral toes to appear in some (not all) horses. Or give some (not all) whales what appear to be atavistic femurs. Or cause pseudogenes or HERVs to corroborate, at least roughly, with phylogenies constructed on independent grounds, even when the relationships are not intuitive, e.g., that between elephants and manatees. Or put a telomere in the middle of the second human chromosome, suggesting the fusion of two ancestral telomeres (which must have happened in one of the first generations if humans are specially created, since we all have these telomeres).

Yes, the Intelligent Designer could have done all these things, and many more, and if we are to follow your counsel, we should refrain from making any conclusions from these phenomena. Yes, s/he/it may have had reasons we cannot comprehend. Yet, if the Designer is not impotent, s/he/it could have created in any of an infinite number of other ways without so much as offering the slightest suggestion that common descent was at play. It wasn't the brutality of nature that concerned me as I contemplated God's role in creation, but rather the sense that s/he/it began to appear deceitful if s/he/it had not in fact used evolution as a tool of creation. In denying evolution, I began to feel like the proverbial creationists who suggested that God deliberately planted fossils of extinct fauna in the earth to test our faith. This was the crux for me: If God, who could have created in any way s/he/it saw fit, chose to create in such a way that common descent made sense, when in fact common descent did not happen, then how could I possibly trust God in any other matter? As E.O. Wilson put it:

"Perhaps God did create all organisms, including human beings, in finished form, in one stroke, and maybe it all happened several thousand years ago. But if that is true, He also salted the earth with false evidence in such endless and exquisite detail, and so thoroughly from pole to pole, as to make us conclude first that life evolved, and second that the process took billions of years. Surely Scripture tells us He would not do that. The Prime Mover of the Old and New Testaments is variously loving, magisterial, denying, thunderously angry, and mysterious, but never tricky [with the possible exception of the story in which God sent a lying spirit to the prophets--Ken] (Consilience, p. 141).

Are you willing to give up truthfulness as an attribute of the Intelligent Designer in an effort to paint evolutionists as theologically motivated? You are willing to put apparent evil on the table; what about deceit? I'd like a straight answer from you on this.

In what ways could God have pre-empted the appearance of common descent, and by so doing, nipped any possible theory of evolution in the bud? In other words, what kinds of show-stoppers could s/he/it have planted? Here are a few:

1) By creating the universe with the appearance of youth, thereby unmistakably denying evolution the time it needed to happen. Instead, we witness supernova explosions up to 9 billion light years away.
2) By making the fossil record follow any of millions of possible sequences other than the one that it in fact follows, with complex forms appearing in only the higher layers.
3) By taking care not to introduce apparent atavisms like hen's teeth and horse toes (to quote the title of a Gould book).
4) By not putting morphologically similar (but significantly different) extinct species in the same geographical location as extant creatures.
5) By creating an inseparable gap between humans and the creatures most closely allied with them genetically. As it is, we share between 95 and 99% of our genome with chimps, and the fossil record provides morphologically intermediate forms between the chimps and us. If cows or dogs were the most similar creatures to us, modern evolution could never have gotten off the ground.
6) By using similar forms (e.g., cartilaginous fins) for similar functions (aquatic maneuvering), rather than different forms (e.g., a pentadactyl structure) for similar functions, differentiated by lines of descent proposed on other independent grounds.
7) By tightly constraining the variability of populations within species such that, for example, the striking variety of dog breeds developed within human history, or human races themselves, could not have arisen.
8) By taking care not to introduce any of the other 29+ evidences of macroevolution discussed in the article of the same title (sans any real theological considerations).

The list could be endless. That things are the way they are does not prove macro evolution, but note that evolution could not be true if reality were significantly different than it in fact is. The world didn't have to be old. It is. Dolphins didn't have to have five fingers. They do. Complex forms could have been found in the lower strata. They haven't been found, nor will they be. If a rabbit skeleton is some day found in the pre-Cambrian, then we can all give up this debate and take a rest, acknowledging the creationists were right all along.

You may protest that none of these phenomena really prove common descent, and that we only come to our conclusions by "connecting the dots." Granted. But this isn't about mathematical proof. For me, it's about looking at the data and thinking, "What really happened?", regardless of what I want to be true, or how capable I might be in highlighting the difficulties in the theory. It's not a game! It's about truth.

The predictive power of evolution impressed me the more I learned of the facts. For example, Nikishimi searched for and found an apparently non-functional vitamin C-producing gene in primates based on the fact that primates do not produce their vitamin C like other mammals. Here is my take on how the discovery proceeded:

1) It was discovered that most mammals do not need vitamin C in their diet;
2) Therefore, there must be a gene that produces vitamin C;
3) Based on (2), we've looked for and found the gene
4) Other mammals, i.e., guinea pigs, primates and humans, require an external source of vitamin C in their diet
5) These mammals therefore must not be able to produce vitamin C on their own.
6) On the theory of common descent, humans and primates share a common ancestor
7) On the theory of common descent, that common ancestor was a mammal
8) On the theory of common descent, that common ancestor or a predecessor, like other mammals, must have a vitamin C gene similar to that shared by other mammals.
9) On the theory of common descent, primates and humans (the descendants of primates) would be expected to have a non-functional vitamin C gene at the same location in the genome as that in other mammals.
10) On the basis of (6) thru (9), we look for that gene and find it in both primates and humans. Furthermore, we discover that this non-functional gene varies among species (humans, chimpanzees, orangs, macaques, etc.) in proportion to the distance between them in the standard phylogenetic tree.

My point here is to show how integral the theory of common descent was to the reasoning that led to the discovery in (10). The kicker is not that humans and primates share some genes in common (like they share many other features), but that the existence of a non-functional (at least in respect to the production of vitamin C) gene could be predicted ahead of time before knowing whether it existed in either primates or humans. It is that specific prediction that sets apart the theory of common descent from its competition. Note that I am not making any of the metaphysical claims you accuse evolutionists of. I am simply saying that, in this case, and in many others, the theory is productive.

From an ID or creationist standpoint, there is no reason to predict that primates should have a vitamin C pseudogene without already knowing it. From an evolutionary perspective, we would think it likely that the genetic remnants of a functional vitamin C-producing gene should exist in the primates if the primates are descended from mammals that have a functional vitamin C-producing gene. What evolutionary theory predicts is the simple existence of the vitamin C pseudogene in primates (before even looking for it under the microscope), not its underlying mechanism. And ID could never have predicted its existence by any non-ad-hoc principle. If it could have, let me know.

As a former missionary linguist-to-be-Bible translator in Africa, I was impressed by the similarities and differences between the language I studied and a neighboring related language. I often thought about the principles I had learned in my one historical linguistic class, and I was fascinated by the patterns I could uncover, and puzzled by the instances that ran counter to the rules. But I never once doubted that the two languages shared a common ancestor. The geographical and morphological proximity of the two languages made it impossible to argue otherwise, in spite of the puzzles. What really happened? In broad lines, they descended from a common ancestor. Exactly how it happened, I have no clue.

You are gifted at drawing out puzzles and challenging the logical basis for our conclusions. But your attempts at undermining common descent ring hollow, simply because nature makes sense when seen through the lens of evolution. For all your prowess, effort and sincerity, you cannot change the facts, and the facts as a whole testify to the veracity of common descent.

By the way, if you do accept the possibility of blind fish having descended from seeing fish, where in my list do you draw the line between what probably did happen and what probably did not happen, keeping open the possibility of an Intelligent Agent to bridge any probability gaps?

I really would like to know where you draw the line and why...

greenbear

Drawing lines? Wouldn't help for one such as CD. Reading this thread highlights a common defect of Evolution deniers. They are immune to heaps of credible scientific evidence but are receptive to the point of absurdity to any harebrained, evidentially unsupported, "crossing over" type pseudo-science promulgated in popular literature as long as it doesn't exclude God.

Charles Darwin

Evolutionist: Evolution is a fact.
CD: Really? What about these scientific problems?
Evolutionist: Oh, so you're saying evolution is impossible huh?

Do you see the false dichotomy here? If I cannot falsify evolution that does not mean it is a fact.

Could, could, could? Yes, any of those transitions could have occurred. They all could have occurred. But they are not what science is pointing to. Surely you can see the difference between a fish losing a complex capability versus a fish becoming a giraffe with all of the additions that that entails.

What is unlikely about your series of transitions? Well, first there is the fossil record. As Carroll observes, the species don't form a spectrum of finely-graded intermedates. They almost always belong to a few, distinct major groups. Darwin's idea of extrapolating the observed small-scale change to macro change is challenged by the fossil record. Even evolutionists today question whether large-scale evolution is merely repeated rounds of small-scale change. Secondly, it is not as though breeding experience or evolutionary experiments reveal that adaptation and variation is unbounded in the sense that you require. All of our practical experience suggests it is not unbounded. Third, as I've already brought up, there is the issue of mutation rates, fixation probabilities, and the overall design space. Fourth, does there even exist such a finely-graded set of intermediates (answer: "we don't know")? Fifth, how did the many new complexities evolve (designs that require multiple DNA substitutions)? Sixth, the small-scale change that we do observe are brought about by a highly complex adaptation system which evolution can only speculate about how it arose. Did evolution build an evolution machine? One which lays out future paths of change (as opposed to randomly exploring the design space).

So is your fish-to-giraffe evolution possible. Sure, all sorts of things are possible. There may be ETs on alpha-centuri too. What I am looking at is science, and what it indicates.

Charles Darwin

quote:
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Originally posted by Charles Darwin
My take is that authors overstretched when they conclude the enamel synthesis genes are still present in a working form in toothless aves. The avian genes they refer to are building block genes used for all sorts of developmental purposes. It is no surprise that they are fully functional; they are used for a variety of purposes. Again, if there was some long since dormant avian set of genes being invoked then they should be riddled with mutations.
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They are not "avian" teeth. Their formation is not a coincidence, they do not form without the mouse tissue applied. The mouse tissue is necessary to have the teeth form. It is causing the teeth to form, and in the process using building block avian genes that are there all the time.

Look, this observation was claimed as strong evidence for evolution because it shows long-dormant avian 'teeth' genes. I explained that this simply is not what the evidence shows, and in fact doesn't even make sense since the genes in all liklihood would be riddled with mutations even if they did exist. Now after explaining this, do you say "OK, I see your point; this isn't such strong evidence." ? No, you continue with this useless claim. OK, I give. That's all I can do. If you still believe it is strong evidence then don't blame me.

Doubting Didymus

What exactly leads you to this conclusion, which is the opposite of that of the actual researchers? It's always intriguing to see that not accepting evolution somehow gives one the ability to simply dismiss any conclusion from any scientist that one does not like very much, based, seemingly, on nothing more than ones humble opinion. Sadly, the rest of us do not have this magical ability.

Edit: It's just occurred to me that you may not have meant what you seem to have meant. Would I be right in thinking that you do, actually, accept the conclusion that avian signals are causing the development of the teeth, but that this should be unsurprising for some reason?

lpetrich

Charles Darwin:
What is unlikely about your series of transitions? Well, first there is the fossil record. As Carroll observes, the species don't form a spectrum of finely-graded intermedates. They almost always belong to a few, distinct major groups.

Except that on the large scale, one does find LOTS of intermediates. Consider horse evolution from Hyracotherium to Equus. Living back in the Eocene, about 50 million years ago, Hyracotherium was about the size of a small dog; its shoulder height was 10-20" (25-50 cm; 2.5-5 hands). It had a more-or-less generalized dentition, and similar-looking toes, 5 in front and 4 in back.

As time goes on, one finds successors to Hyracotherium that get bigger and bigger, get bigger and bigger cheek teeth (premolars and molars), and get bigger and bigger middle toes -- and smaller and smaller toes on each side. Eventually, they get one big middle toe and two small side toes, and eventually only one toe.

But present-day equines are sometimes born with two extra side toes on each foot!

But what does CD think had happened? *POOF!* *POOF!* *POOF!* *POOF!* *POOF!* ?

Also look at the hominid/hominin fossil record. The earlier ones look very simian and the later ones look more and more human.

(CD's demands of very rigorous standards of proof...)

I dare him to demand equally high standards of proof for his pet hypothesis of the miraculous creation of new species.

Doubting Didymus

You've seen this picture already, I think:



What major groups were you referring to in this case?

Badfish

Why does "D" have an unnatural blue glow? Heeeeey is there some CGI going on here?


I've seen this a hundred times, some could be monkeys, and may I ask if anyone has actually seen these skulls in real life? Or have you just seen the pictures?

Oh yeah, also "L" gives me the creeps.....

Azathoth

It's the material used to fill in the gap.They just copy from the other side,since skulls are symmetrical.