Gracchus

The only real reason creationists deny evolution, is that it destroys the argument from design, the last tenable "proof" of the existence of God.
Do you suppose that creationists will ever take God on faith?

gabe

Gracchus,

What do you mean by "design"? and how is evolution at odds with such a notion?

Doubting Didymus

Gracchus refers to the intelligent design of organisms by a supernatural agency. This notion is not only at odds with evolution, but goes against the principles of all science.

Gracchus

The "argument from design" I was referring to was the last viable "proof" of the existence of God. Evolution shows that argument to be invalid. Creationists need that "proof" to shore up their puny faith. Science is crowding out the "God of the Gaps", and the creationists are becoming increasingly uncomfortable.

Lobstrosity

Don't worry, I know you were just kidding around with that part of your post. I was just playing along. I actually very much look forward to your response, however, if you can find the time.

Doubting Didymus

Ditto.

Actually, I suspect I've been hogging the creationists of late. I think I'll take a small step backwards and let someone else have a turn for a little bit.

Silent Dave

Fair enough. So that just leaves the question: who IS Mike? Is he a well-known creationist? Does he have a website?


Dave

Bialar Crais

Donthca know? Mike is a fair dinkum thinkum. However, that's all that can be told about him lest the Authority finds out and nulls him... That would be disastrous to the Loonie Revolution. TANSTAAFL!

theyeti

Okay, sorry about the delay. Gabe, you are welcome to forward this to your friend Mike if you'd like, but I can't promise that I can keep continuing this back and forth, especially since we're covering almost everything, which is tedious. It would be better to pick a particular topic and stick to it. But I'll do what I can.

Not quite. Selection is quite testable by viewing it at work today. We can for example see it at work in the lab with bacteria, viruses, and other organisms, as well as selective breeding of proteins, which has proven to be superior to rational design for making novel enzymes. You can then extrapolate backwards for any length of time, though of course the specific selective pressures will often remain beyond our ken. The mechanism, however, is quite testable. This isn't the case with "God". No one can witness the god-mechanism at work today, and it can't even be established scientifically if God exists. And furthermore, specific selection scenarios can be tested if certain outcomes are predicted by certain scenarios. For example, if we think that protein A may have evolved from protein B, we test this by looking for homology between the two. It gets more complicated with larger systems, but it's easy to rate some evolutionary scenarios as being more consistent with the evidence than others. You couldn't do that if they weren't testable.

Much faster than predicted by what?! This is obviously a veiled reference to the Cambrian Explosion, but to my knowledge no one has ever calculated that the rate of evolution during the Cambrian exceeds what is allowed by natural selection. Creationists like to claim this, but I've never seen anywhere that they back up this claim with any hard evidence -- they just say so and leave it at that. The CE took place over a minimum of 5 million years; some say much longer. That is already much too long of a time frame for the human imagination to wrap itself around. The whole point of "gradualism" (not to be confused with what the Punc Equers are against) is that new species come about incrementally rather than all at once. The CE was not all at once! Different groups of animals appeared at different times during the CE. To be sure, it was a rapid burst of evolution the likes of which have not been seen since, but there are a number of theories to account for it. It was in all likelihood a unique event, though there are certainly those who argue otherwise.

Rather than go into all sorts of detail about the CE, I will simply provide some links that can be perused at will (note: They'll have to wait until my next post unless others here are kind enough to provide them). I will say this much: The CE is an exceptionally weak argument for creationists to pull out. Mostly because one has to willfully ignore the past 600 million years of Earth history, which comprises the vast majority of metazoan evolution, and even worse, one has to assume evolution before one can claim that the Cambrian is an oddity. No Cambrian animal bears any resemblance to modern fauna, except for having certain primitive characteristics which allow us to identify them as our ancestors. Please make note of this! If it weren't for the fact that the evidence is consistent with evolution, creationists couldn't even claim that all of the "body plans" came about within a short amount of time. If "body plans" seemed to come about from nowhere willy-nilly all throughout Earth history, then that would be the real problem for evolution. But as it stands, there is a record of continuous change going all the way back to the Cambrian. The real problem is that we lack a good pre-Cambrian record, which makes it hard to say where the Cambrian fauna came from. Nevertheless, the amount of change that has taken place since is impressive. The Cambrian chordate Pikia looks more like a glorified worm than it does a bird, mammal, or fish; which means that an awful lot of evolution must have taken place after the Cambrian -- evolution subsequently ignored by creationists. We classify Pikia as a chordate because it has the diagnostic character of having a notochord, among a few other characters I think. And this means that it might be our ancestor. So how is this supposed to be evidence aginst evolution? The CE argument doesn't even make sense unless one assumes that all animals are descended from the Cambrian fauna, in which case you've ceded 90% of all metazoan evolution, including the common ancestry of all mammals, birds, insects, and so forth.

This brings up another issue. The fact that most phyla appear in the Cambrian comes as no surprise to anyone familiar with systematics. Classifications are human inventions. They are non-arbitrary in the sense that we can't go about classifying organisms any which way we choose (more on this later), but they are arbitrary in that we can draw a circle around any monophyletic group (that is, an ancestor and all of its descendents)
and give it a name. As it stands, we only do this with a handful of monophyletic groups -- genera, families, orders, classes, phyla, and so forth -- which are only a tiny percentage of all possible monophyletic groupings. This is exactly why the field is plagued with "splitter"s and "lumpers" who keep inventing new categories. The issue here is that the more inclusive a monophyletic group is, the further back in time its first appearance must necessarily be. For example, the first appearance of a vertebrate must necessarily predate the first appearance of a mammal, since vertebrates are a more inclusive group of which the mammals are a part (in other words, their *nested* within the vertebrates). The first appearance of Kingdom animalia must predate the appearance of the vertebrates; the first appearance of Class mammalia must predate the first appearance of Order primates, and so on. What this means is that if you take the most inclusive grouping of animals, which is to say the phyla, you will necessarily find them first appearing back during the earliest radiation of animals. This doesn't tell us anything special; it's just an expected consequence of our classification system due to the fact that there is no more inclusive grouping within the animals. If we were to label a later animal as the first appearance of a new phylum (and remember, the category "phylum" is arbitrary -- we could call mammals a phylum if we wanted to), we've now made whatever phylum it's derived from paraphyletic (which means containing an common ancestor and some, but not all, of its descendents). For example, making the mammals their own phylum would make the phylum chordata paraphyletic, which is something that systematicists try to avoid. Of course this is a problem at the lower levels too. The reptiles, for instance, are paraphyletic because they include all amniotes except for birds and mammals. This is why cladists would like to do away with traditional classifications altogether. Sorry that this is getting a bit long-winded, but the point is that the appearance of all phyla near the beginning of the first metazoa is expected due to our way of classifying organisms. It hardly counts against evolution.

Than expected by what or by whom? Does this guy have anything to back this up with? The observed rate of change for species today is high enough to account for all of the observed change in the fossil record, and then some. The mutation rate is also high enough to account for all molecular evolution and then some. A useful discussion of this can be found at the site I lined to above, and particularly instructive is this quote:

Our observations in this case do not contradict theory.

Nope, it's easy to test. Take a population of bacteria. Let them become as genetically diverse as they want. Then apply an antibiotic. You'll end up with only one or a few survivors, who will then begin growing into colonies consisting of genetically identical clones. You can keep the populations genetically homogenous forever in this fashion, as long as the selective pressure is high enough. Here's another example: Introduce a terrible disease into a population of anything. You kill off 99% or more of its members, and suddenly the population is much more genetically homogenous than before. All future descendants come from only a handful of survivors. Bottlenecks such as these occur constantly throughout nature, and they've been doing so all throughout Earth history. What happened when the asteroid killed the dinosaurs at the end of the Cretaceous? Variation went down, not just for each individual species, but also for the entire biosphere. It took a long time for it to come back to its previous levels. Mutation is continually inserting variation into the population, and selection is continually taking it out. The key is that while mutation inserts variation more or less randomly, selection does not remove it randomly. It removes the non-adaptive variation at a much higher rate.

Again, the mechanism of selection is exceedingly easy to test, and as long as you're observing organisms in real time, you can tease out the selective pressures. Just look for cause and effect in regards to death and survival, and what's causing greater reproductive rates. Besides, this statement appears to be incongruent between the earlier claim that variation was not as large as it "should be." That claim seemed to implicate variation as seen today among contemporary species, not among what's seen in the fossil record. We don't see much variation in the fossil record for the mere fact that most species are only known by a handful of specimens, sometimes only one. And we're lucky if we get a mostly complete skeleton -- you can forget soft body parts, coloration, behavior, genes, proteins, and bunches of other selectable characters. Those things don't fossilize. Nevertheless, we can extrapolate and figure that processes observed today are the same as they were millions of years ago. We don't assume that because we've only found one specimen of a given species that only one existed. That would be silly. We assume that a large and interacting population existed, because that's what's true of contemporary organisms. Likewise, we can extrapolate variation and selection backwards, and we find that contemporary rates are more than sufficient to account for evolution. Now one might object to such extrapolation, but it merely rests on the assumption that the laws of nature are constant in time and place. This is no different than what geologists and astronomers do on a regular basis, and what pretty much all scientists do at least occasionally. There are sometimes reasons to be skeptical of extrapolating, for instance during the earliest times when conditions and genomes may have been much different, but to dismiss it out of hand makes it impossible to do any science at all.

The evolutionary process has limitations on it. It works by a readily observable mechanism. It is testable.

There's an unfortunate tendency for creationist to bounce back and forth between two styles of argument: The first holds that evolution has been falsified by some particular bit of evidence. When that line of argument fails, then suddenly the claim is made that evolution is not falsifiable. Well, if that were really the case, then the first line of argument could have never been pursued in the first place. Many creationists try to argue both simultaneously, which is clearly disingenuous because both can't be true. But in this case neither are. It's not as if there are only two possiblities: false or unfalsifiable. There is a third possibility, which holds in this case, and that's that evolution is falisfiable yet currently unfalisified. The article that I linked to above explains how evolution could be falsified by the very issue that's brought up here, but the fact remains that it passes the test. For example, if observed mutation rates could not account for molecular divergence between two organisms over a reasonable amount of time, then that would be extremely problematic for evolutionary theory. But as it is, mutation rates are generally far beyond what would be necessary to account for sequence divergence.

Of course there would be. It's informative to know whether or not humans and chimpanzees share a common ancestor regardless of how life first started. It's also informative to know how one species can evolve into another, or how one gene with one function can give rise to two genes with two functions. This is like saying that there would be no reason to do research on stellar evolution if we didn't believe that the universe had a fully natural beginning.

Miller's experiments were never discredited! The problem with them is that they used a highly reducing atmosphere, whereas the real early Earth atmosphere was probably weakly reducing. You still get amino acids with a weakly reducing atmosphere, and to a certain extent with a neutral atmosphere as well. Furthermore, Miller's experiment was corroborated by the Murchison meteorite, which was found to have the same amino acids in the same ratios. So the process that Miller discovered was certainly acting somewhere in the early solar system, which is significant because many researchers believe that comets and meteors brought many organic material to Earth. The fact of the matter is that we've moved beyond Miller's early experiments and have discovered a variety of ways that organic chemical might have been produced.

The only reason that origin of life research is "unlinked" from evolutionary biology is that the two run off of totally different processes. Evolution works by mutation and selection -- you can only have this if you have a replicator with less than perfect fidelity. Obviously, the very first replicator couldn't come about this way, so origin of life research focuses on chemical self-organization. Of course there's some overlap between the two, but then again there's overlap between evolutionary biology chemistry. You wouldn't say that evolution was in trouble because we didn't know all of the laws of chemistry.

And origin of life research is hardly "slow" and has hardly run its course. It's proceeding at quite a decent pace. The RNA world was only proposed back in the 1980s, and has since become well established. Pre-RNA worlds are now being explored, along with a number of other concepts. But the real irony here is that creationists or intelligent design "theorists" are poorly positioned to point to slow research as being problematic for a theory -- these guys have yet to accomplish one spec of useful research.

Well, I addressed that above. But anticipated by whom? The Cambrian explosion was known about in the time of Darwin. At most it's just an anomaly, and invoking it still leaves the rest of Earth history and the patterns therein unaccounted for.

Only in the sense that everything is neutral for creation. If you have an omnipotent creator that is allowed to be capricious, then there is nothing that could possibly rule it out. It can however be dismissed for being unparsimonious and superfluous.

The whole point of either evolution or creation is to explain adaptation. The fact that adaptation exists automatically means that there are selectable phenotypes. If there weren't, then we wouldn't recognize organisms as being well adapted. Now if one wishes to argue against selectable intermediate phenotypes, then that's a separate issue. But arguing against the mere existence of selectable phenotypes makes little sense.

Whether or not the evidence is consistent with the creation model depends entirely on what the creation model is. Are we talking young Earth or old Earth here? All at once or progressive? Flood or no flood? How is the fossil record interpreted? There needs to be a specific model about what happened when and how before we can say if the evidence is consistent with the model. The mere statement that "life was created" is not testable. So there needs to be something more specific.

Yes, but even if we accept this we haven't really explained anything. Simply saying that it must have been supernatural just slaps a label on it. Unless someone can find a way to adjudicate between various supernatural processes using some sort of empirical evidence, then invoking the supernatural will remain useless to science. Given the very definition of supernatural, that's not likely ever to happen. As it stands, those who try to find evidence for the supernatural rely exclusively on the supposed inability of natural processes to do the trick (if they're not invoking faith or revelation that is). But the problem is that one would have to search exhaustively through all possible natural processes -- including those we might not have thought of yet -- before being able to accept the supernatural by a process of elimination. It's the classic god-of-the-gaps argument, and it's widely rejected by scientists, philosophers, and even theologians. If this is the "creation argument", then it needs to be reformulated into something that can be tested against the empirical evidence before it becomes a useful competitor with evolutionary theory. In other words, it needs to be an actual theory, and not just an argument.

Okay, so does creationism make any testable claims?

************

Sorry, I'm going to have to cut it off there. I'll try to get around to the rest of it tomorrow.

theyeti

Jobar

theyeti:
Are we talking young Earth or old Earth here? All at once or progressive? Flood or no flood? How is the fossil record interpreted?

I was curious about that, too. I think we can safely presume that Mike is a YEC; else why attempt to deny evolution? Were he an OEC, then like some of our Christian-evolutionist posters, he could attribute abiogenesis to God and accept evo lock, stock and barrel.

And that means we can clobber him with geological evidence that the Earth is ancient, as well as the evo arguments.