Friday, November 20, 2009

 

Ken Miller's Ankles Are In Danger


Oh, my goodness!

The Discovery Institute's attack chihuahua, Casey Luskin, is actually taking a page out of Answers in Genesis' (and about every other young-Earth creationist organization's) book. It is the ol' "we are using the same evidence but just interpret it from different starting points" ploy.

In responding to what Luskin characterizes as Ken Miller's argument that evidence for common descent refutes Michael Behe's "irreducible complexity" claims, Luskin says:

[A] piece of evidence Dr. [Kenneth] Miller commonly cites as demonstrating human/chimp common ancestry is the fusion of chromosome 2 in humans, which he argues has a structure similar to what one would expect if chimp chromosomes 2a and 2b were fused together, end to end. Without belaboring the details (which are covered elsewhere), the evidence for human chromosomal fusion simply indicates that our ancestors once had 48 chromosomes. But it tells us nothing definitive about whether our lineage leads back to a common ancestor shared with with apes. Human chromosomal fusion merely shows that at some point within our human lineage, two chromosomes became fused. That's it.

If we step outside the Darwinian box, then the following scenario becomes possible: (1) The human lineage arose separately from that of apes with 48 chromosmes, (2) a chromosomal-fusion event occurred, and (3) the trait spread throughout the human population. In such a scenario, the evidence would appear precisely as we find it, without any common ancestry between humans and apes. The two diagrams at right show two models for explaining the evidence for human chromosomal fusion.

At most, the fusion evidence confirms something we already knew: humans and apes share a similar genetic structure. But this might have been predicted by morphological studies without considering evolution. Again, common design can also account for such functional genetic similarities, and the fusion evidence does not demonstrate that humans share a common ancestor with apes.

Dr. Miller may reply that his model predicts the fusion evidence. But if we didn't find evidence for fusion in human chromosome 2, would that really refute Darwinism? No. Evolutionists would just claim that the fused telomeres and extra centromere were deleted. Miller assumes that functional genetic similarities must result from common descent, ignoring the possibility that such biochemical similarities might result from common design upon a functional blueprint.
Luskin even produces a diagram to "illustrate" his point:


First, let's get Miller's argument from his own mouth, rather than as spun by Luskin and the other IDers:

We've known for a long time that we humans share common ancestry with the other great apes—gorillas, orangs, chimps, and bonobos. But there's an interesting problem here. We humans have 46 chromosomes; all the other great apes have 48. In a sense, we're missing a pair of chromosomes, two chromosomes. How did that happen?

Well, is it possible that in the line that led to us, a pair of chromosomes was simply lost, dropping us from 24 pairs to 23? Well, the answer to that is no. The loss of both members of a pair would actually be fatal in any primate. There is only one possibility, and that is that two chromosomes that were separate became fused to form a single chromosome. If that happened, it would drop us from 24 pairs to 23, and it would explain the data.

Here's the interesting point, and this is why evolution is a science. That possibility is testable. If we indeed were formed that way, then somewhere in our genome there has to be a chromosome that was formed by the fusion of two other chromosomes. Now, how would we find that? It's easier than you might think.

Every chromosome has a special DNA sequence at both ends called the telomere sequence. Near the middle it has another special sequence called the centromere. If one of our chromosomes was formed by the fusion of two ancestral chromosomes, what we should be able to see is that we possess a chromosome in which telomere DNA is found in the center where it actually doesn't belong, and that the chromosome has two centromeres. So all we have to do is to look at our own genome, look at our own DNA, and see, do we have a chromosome that fits these features?

We do. It's human chromosome number 2, and the evidence is unmistakable. We have two centromeres, we have telomere DNA near the center, and the genes even line up corresponding to primate chromosome numbers 12 and 13.

Is there any way that intelligent design or special creation could explain why we have a chromosome like this? The only way that I can think of is if you're willing to say that the intelligent designer rigged chromosome number 2 to fool us into thinking that we had evolved. The closer we look at our own DNA, the more detailed a glimpse we get of our own genome, the more powerful the evidence becomes for our common ancestry with other species.
Note what Miller is really saying here: we have lots of evidence that we share common ancestry with the other great apes (heck, even Luskin has to admit that "humans and apes share a similar genetic structure") but, when we encounter something that raises a question how close that relationship is -- our different number of chromosomes -- and we go and look, we find convincing evidence that it is as close as we originally thought. If we hadn't found the fused chromosome, it would not have refuted evolution or common descent but it would have greatly changed our ideas about the relationship between gorillas, orangutans, chimps, bonobos and human beings. In short, it supports the other evidence that led us to think there was not just shared ancestry, but a close relationship.

What is Luskin's response to this evidence? Not wanting to go the "trickster Designer" route, he can only fall back on a presumption that there is a "Designer" and simply say that, if you look at the same evidence with their presumption, you can mangle it to fit their preconceived idea ... i.e. "the possibility that such biochemical similarities might result from common design upon a functional blueprint."

But why would a "Designer" abandon the "common design" of an already "functional blueprint" to fuse the human version of chromosomes 12 and 13, shared by all other primates? Now here is a research project that the Biologic Institute could take on: find the functional reason to fuse these two chromosomes. Otherwise, IDers are just offering a reason to ignore one piece of the massive total evidence, gathered across numerous lines of investigation in many different fields, that forms a consilience favoring common descent of all the great apes, including humans, and evolution in general.

Remember how Stephen Meyer crows about using "the same method of inferential reasoning that Darwin used," namely: "the inference to the best explanation"? When you take all the evidence, instead of selectively ignoring the evidence that your theory does not even attempt to explain, the best inference clearly favors common descent through processes that can be naturalistically explained.

And no amount of ankle biting can change that.

______________________________

Update: "NickM" asked in the comments if Luskin wasn't arguing that the originally created humans had 48 chromosomes which later fused; not that the creator fused them himself. If so, then the Biologic Institute wouldn't have to find the functional reason to fuse the two chromosomes (though there'd still be the question why the "Designer" didn't build in safeguards to prevent random fusing of chromosomes, which could be catastrophic).

But now we learn from Stephen Meyer (via Richard Hoppe at The Panda's Thumb) that:

If an intelligent (and benevolent) agent designed life, then studies of putatively bad designs in life–such as the vertebrate retina and virulent bacteria–should reveal either (a) reasons for the designs that show a hidden functional logic or (b) evidence of decay of originally good designs (Signature in the Cell, p. 497).
So, if the "Designer" didn't originally and intentionally fuse our chromosomes for some reason to improve his already "functional blueprint" for primates, there should be evidence that human chromosomes are inferior to the rest of the great apes. Still something the Biologic Institute could get its teeth into ... if it had any.
.

Comments:
This "interpret the evidence differently" line means in practice "interpret the evidence so that it isn't evidence any more".

Transparent special pleading.
 
Remember how Stephen Meyer crows about using "the same method of inferential reasoning that Darwin used," namely: "the inference to the best explanation"?

Well, "the designer did it" IS a very short explanation. We have to give them that.
 
Except it is no explanation at all since it would fit whatever had happened equally well. The 'explanation' "The designer wanted/made it that way." would be the same whether the "it" was 'We kept 24 chromosome pairs.' or 'Two of our chromosome pairs fused.'

'The designer wanted/made it that way.' has no more explanatory value than 'Orange!'
 
Dang. That immediately preceding Anonymous was Mike from Ottawa who doesn't like anonymous posts.
 
John -- nice post, but isn't Luskin arguing that the originally created humans had 48 chromosomes which later fused, not that the creator fused them himself? Still silly but slightly different...
 
This is a prime example of the common creationist ploy -taking each piece of evidence in isolation, while ignoring all other supporting evidence, i.e. consilience. This is especially egregious in Explore Evolution, by Meyer et al, the DI faux textbook reviewed in Reports of the NCSE, July-August 2009, by John Timmer.

Bob Carroll
 
... isn't Luskin arguing that the originally created humans had 48 chromosomes which later fused, not that the creator fused them himself? Still silly but slightly different...

Hmmm ... I suppose so, but then the question just becomes why the "Designer," who can apparently forsee all possible combinations of chemistry over millions, if not billions, of years didn't build in safeguards for his "functional design" so it wouldn't risk catastrophe by randomly fusing genes. Either the fusion was part of the design or it shows bad design. And if we can't tell whether the fusion was designed or random, how can we tell any other feature of life is designed or not?
 
"Now here is a research project that the Biologic Institute could take on: find the functional reason to fuse these two chromosomes."

John, John. It's simple: The Designer is just fucking with our heads. As both Jonathan Witt and Billie Dembski have said, He's a whimsical old deity.
 
Those guys were just parroting Phillip Johnson:

"It seems to me that the peacock and peahen are just the kind of creatures a whimsical Creator might favor, but that an “uncaring mechanical process” like natural selection would never permit to develop."
 
Does the Discovery Institute care to speculate when the 'fusion event' happened?

If they say it happened a few million years ago then they will fall out with a lot of Young Earth Creationists. If they sat it happened less than 10,000 years ago, then they will have to tie it to some myth point like 'the fall' - or deny the significance of a designer led event.

Tricky choice for the DI - and one they skirt around on many issues.

Does science estimate a date for the natural fusion event?
 
Dr. Miller uses the human chromosome 2 evidence to demonstrate that common ancestry generates testable predictions that are consistently confirmed.

In order to argue against Miller's point, Luskin must portray Miller's demonstration of the predictive power of evolution as an attempt to demonstrate human/chimp common ancestry.

That's dishonest.
 
Actually Luskin missed point totally. If Miller's fusion have been happened AND the deletion would be happened also, then it perhaps not falsifying the evolution.

BUT if the orders of genes are scrambled, ts: Same genes are in totally different order in "fusion_claimed" chromosome, it would be big problem for evolution. "Many and many mutations needed." That makes it quite unpropable.

Of course design "could" order them in the same. But if they are scrambled, that would not falsify Design.

TS: There is actually easy_to_see evidential difference. There is "can be", and "there would be quite a heck more propable A than B". The way C.L. uses evidence is "very rough". So rough it is uncertain it is anymore even an argument.

Propabilistic approach is totally forgotten. "YES-NO" is only way they can look. Perhaps that's why they are so dichotomic in every areas of their argumentation?
 
Dr. Miller should come out okay if he wears his high-top sneakers.
 
The real question is what does this fused chromosone prove ? That
apes and man branched off some evolutionary tree, or that two unique life forms shared a similar
pathology without ever being connected so close. Life could be
more of a cluster of vines, not a tree. Then alien life forms in the same environment may crossbreed
by retro viruses, so that after time, all the life forms in the same environment become ancestral
without ever being originally truncated to one common origins
of life.
 
The fused chomosomes don't "prove" anything in and of themselves. As I said originally, it supports the other evidence that led us to think there was not just shared ancestry, but a close relationship between humans and the other apes.

This is the common ploy of creationists of considering the evidence (when it clearly does not support their own "hypothesis") as individual "proofs" instead of as a piece in a much larger puzzle. The power of evolutionary theory is its consilience ... the ability to explain massive amounts of facts, across numerous diciplines, in a consistent manner. Positing a designer who merely creates, in unknown ways, at unknown times, for unknown reasons, whatever it is that we happen to find in the world explains nothing. If you are uninterested in explanations, then you are uninterested in science.

You're free to take that attitude and to hold any theological position you want, but you and ID apologists are not free to call it science in a public school classroom. Nor can you justly complain when scientists don't take you seriously.
 
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up the good work!

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