unintelligent design.

[chickenman]

Whenever I hear that DNA homology is due to "design" and not common descent, I whip out this evidence;

http://www.talkorigins.org/faqs/molgen/

(I realise some of you have an aversion to talk.origins similar to a vampire's revulsion for light. Skim over the authors explanations if you want, just look at the evidence he is presenting.)

I haven't ever heard a satisfactory explanation from an IDist for this. Either I get ignored or they spout something about "scientists don't know for certain that junk DNA is junk" (If you use this I expect you to be able to explain what function it has and to back it up with evidence)

So IDists and YECers, what explanation is there for these shared errors that can be reconciled with special creation/intelligent design?

 

[Jerry Smith]

It is difficult to discuss the evidence of homology with a creationist. You can point to homology (whether genotypical or phenotypical), and you usually be given the answer "A common designer would use similar structures for similar functions." Well, you do have some similar structure and similar function in evolution, but the more telling trends are these:
1) Similar structure for different functions (in more closely related organisms), and
2) Different structures for similar functions (in more distantly related organisms).

An example of the first is the forelimb structures of mammals. A dolphin's fin, a human's arm, and a bat's wing all have very similar structures. All of the bones in the human arm and hand are in the dolphin's fin and the bat's wing. They have differences in shape and relative size that allow them to be used for the various adaptations that are their function, but they are all very similar to one another in general morphology.

Two examples of the second are bird wings and bat's wings, or shark's fins and dolphin's fins. Although the adaptations have similar functions, the less closely related organisms (by all evolutionary scenarios) have radically different bone structures to accomodate them.

A common designer does not explain features like this (at the very most it can be stretched to accomodate them, at the least "we don't know the mind of God - there is a hidden purpose in this pattern").

Common descent strongly predicts features like this, since adaptations must always be applied to structures that are inherited from an ancestor.

Another evolutionary adaptation that does not yield to the "common designer" explanation is one that I don't understand well enough to relate or defend. I am given to understand that there are a few (especially virulent) bacteria that have "irreducibly complex" mechanisms specifically for getting around the human immune system. This would seem to imply that there were two designers: one to design an irreducibly complex human immune system, and one to design a mechanism to thwart it. The fact is that it is not impossible (as some claim) for a system to evolve irreducible complexity, and that the evolutionary scenario explains these two competing systems more accurately and consistently than does a design scenario.

 

[seebs]

I always thought the structural similarities were a pretty obvious thing. I've accepted some kind of common descent since I first understood how a cat's hind legs are jointed. The joints are spaced differently from ours, but they're the same joints.

 

[npetreley]

It's filled with dumb arguments. For example, "If you could prove one functionless sequence actually had a function, that would leave hundreds of thousands of functionless sequences." Even if there is such a thing as functionless sequences, this logic is flawed. One could just as easily state that "If you could prove one functionless sequence has a function, you could eventually prove all of them have a function."

The whole article is filled with this kind of mental masturbation typical of talkorigins.

 

[Jerry Smith]

Sounds like someone needs to take his Vitamin C supplements... that is because our vitamin C gene is broken in the same way that the chimpanzee's is.

Here is another bit of something that "Common Designer" must stretch somewhat to explain:

This is found here:
http://www.gate.net/~rwms/hum_ape_chrom.html

The biggest single chromosomal rearrangement among the four species is the unique number of chromosomes (23 pairs) found in humans as opposed to the apes (24 pairs). Examining this difference will allow us to see some of the differences expected between common ancestry as opposed to a common designer and address the second creationist objection listed above.

There are two potential naturalistic explanations for the difference in chromosome numbers - either a fusion of two separate chromosomes occurred in the human line, or a fission of a chromosome occurred among the apes. The evidence favors a fusion event in the human line. One could imagine that the fusion is only an apparent artifact of the work of a designer or the work of nature (due to common ancestry). The common ancestry scenario presents two predictions. Since the chromosomes were apparently joined end to end, and the ends of chromosomes (called the telomere ) have a distinctive structure from the rest of the chromosome, there may be evidence of this structure in the middle of human chromosome 2 where the fusion apparently occurred. Also, since both of the chromosomes that hypothetically were fused had a centromere (the distinctive central part of the chromosome), we should see some evidence of two centromeres.

Human Chromosome 2 and its analogs in the apes

The first prediction (evidence of a telomere at the fusion point) is shown to be true in reference 3 . Telomeres in humans have been shown to consist of head to tail repeats of the bases 5'TTAGGG running toward the end of the chromosome. Furthermore, there is a characteristic pattern of the base pairs in what is called the pre-telomeric region, the region just before the telomere. When the vicinity of chromosome 2 where the fusion is expected to occur (based on comparison to chimp chromosomes 2p and 2q) is examined, we see first sequences that are characteristic of the pre-telomeric region, then a section of telomeric sequences, and then another section of pre-telomeric sequences. Furthermore, in the telomeric section, it is observed that there is a point where instead of being arranged head to tail, the telomeric repeats suddenly reverse direction - becoming (CCCTAA)3' instead of 5'(TTAGGG), and the second pre-telomeric section is also the reverse of the first telomeric section. This pattern is precisely as predicted by a telomere to telomere fusion of the chimpanzee (ancestor) 2p and 2q chromosomes, and in precisely the expected location. Note that the CCCTAA sequence is the reversed complement of TTAGGG (C pairs with G, and T pairs with A).

The second prediction - remnants of the 2p and 2q centromeres is documented in reference 4. The normal centromere found on human chromosome 2 lines up with the 2p chimp chromosome, and the remnants of the 2q chromosome is found at the expected location based upon the banding pattern.

Some may raise the objection that if the fusion was a naturalistic event, how could the first human ancestor with the fusion have successfully reproduced? We have all heard that the horse and the donkey produce an infertile mule in crossing because of a different number of chromosomes in the two species. Well, apparently there is more to the story than we are usually told, because variations in chromosome number are known to occur in many different animal species, and although they sometimes seem to lead to reduced fertility, this is often not the case. Refs 5, 6, and 7 document both the existence of such chromosomal number differences and the fact that differences do not always result in reduced fertility. I can provide many more similar references if required. The last remaining species of wild horse, Przewalski's (sha-val-skis) Wild Horse has 66 chromosomes while the domesticated horse has 64 chromosomes. Despite this difference in chromosome number, Przewalski's Wild Horse and the domesticated horse can be crossed and do produce fertile offspring (see reference 9).

Now, the question has to be asked - if the similarities of the chromosomes are due only to common design rather than common ancestry, why are the remnants of a telomere and centromere (that should never have existed) found at exactly the positions predicted by a naturalistic fusion of the chimp ancestor chromosomes 2p and 2q?

 

[npetreley]

Originally posted by Jerry Smith
Sounds like someone needs to take his Vitamin C supplements... that is because our vitamin C gene is broken in the same way that the chimpanzee's is.

That makes it -- what? -- the millionth time you guys brought up the vitamin C argument? Why not take this to its natural conclusion? Chimps have eyes, we have eyes, therefore we have common ancestry.

Oh, that's right. What makes THIS different is that it's supposedly a shared harmful mutation. And it's such an effective argument that this is not intentional design by the Creator but a "harmful mutation in common ancestry," since all creatures with this trait went extinct.

ROFL!

 

[Jerry Smith]

And it's such an effective argument that this is not intentional design by the Creator but a "harmful mutation in common ancestry," since all creatures with this trait went extinct.

Who said anything about it being harmful? Its just that the gene - which is there, no longer codes for Vitamin C, because of a slight change in its sequence. It is at the same locus that the Vitamin C gene is in many other organisms, it has most of the same nucleotides in basically the same order as the Vitamin C gene has, yet it does not code for Vitamin C.. Sure this can be harmful on a sea voyage, or in times when the banana crop is short, but that isn't the point. The point is that a designer is a poor explanation for this one. You must postulate a designer that wanted Chimpanzees and Human's not only to be incapable of manufacturing vitamin C, but also to have the genetic hardware for doing so, yet remaining incapable of it anyway. It's not impossible that there is such a designer, but the theory of evolution accounts for this similarity between chimps and humans much more concisely, without stretching the imagination.

 

[Jerry Smith]

I hope you did notice that the Chromosome fusion that was discussed after the Vitamin C remark was a completely separate line of evidence. Sure, it points in the same direction as the rest of the evidence, but that doesn't prove conclusively that there was no Special Creation from Dust - it just strongly indicates that our knowledge of evolution is a fair representation of the reality of the natural world!

 

[npetreley]

Originally posted by Jerry Smith


Who said anything about it being harmful?

I guess I misunderstood what you meant when you said in another thread...

Due to a broken gene that we share with chimps, but that exists in its working form in most other mammals.

When something is "working" and then is "broken" due to a supposed "mutation," I understood that to mean the mutation was harmful. Silly me.

 

[Jerry Smith]

As I mentioned before, the vitamin - c mutation isn't necessarily deleterious (though it can be...). In much the same way that some of the genes that control gill development are broken or supressed, the vitamin c gene in humans just doesn't code for vitamin c... And it doesn't in Chimpanzees either. And the break is the same kind. The broken genes that control gill development in humans (or tooth development in chickens for that matter) aren't harmful.. they are just there. The interesting thing is that one really has to stretch their imagination to explain these by the "common designer" hypothesis, but they are predicted by evolutionary theory.

 

[LiveFreeOrDie]

Originally posted by npetreley
It's filled with dumb arguments.

There's an intelligent response.

For example, "If you could prove one functionless sequence actually had a function, that would leave hundreds of thousands of functionless sequences." Even if there is such a thing as functionless sequences, this logic is flawed. One could just as easily state that "If you could prove one functionless sequence has a function, you could eventually prove all of them have a function."

Actually, it's your logic that is flawed.  It does not follow that because you find a function for one functionless sequence that you must be able to eventually find functions for them all.  Let's rephrase your little bit of logic:

"If you could solve one unsolved murder, you could eventually solve all of them."

Clearly, being able to solve one unsolved murder has no bearing whatsoever on whether or not you can solve the remaining murders.   If you somehow found out who killed JonBenet Ramsey, would that somehow give you some insight to who killed Jimmy Hoffa?

The whole article is filled with this kind of mental masturbation typical of talkorigins.

Oh yes, and your posts are the model of intelligent, well reasoned discourse.  Come on!  Stop the silly hand waving and address the "dumb arguments".

 

[chickenman]

npeterly, I really don't care whether you think the arguments are stupid, I want to hear an explanation for these homologous regions of DNA, like ALU and LINE repeats. Why do humans and chimps have them in the same places?

 

[seebs]

If I can't show you what's wrong with an argument, I generally won't claim it's dumb.

 

[RufusAtticus]

Originally posted by seebs
I always thought the structural similarities were a pretty obvious thing. I've accepted some kind of common descent since I first understood how a cat's hind legs are jointed. The joints are spaced differently from ours, but they're the same joints.

I had that realization when I was young too, although I think it was our dog.

 

[Late_Cretaceous]

"I always thought the structural similarities were a pretty obvious thing. I've accepted some kind of common descent since I first understood how a cat's hind legs are jointed. The joints are spaced differently from ours, but they're the same joints."

I once pointed this out to a creationist in a verbal "debate", to which his reply was "why are a dog's knees backwards". When I said that was the dog's heel, he dismissed me and the whole debate .

 

[seebs]

Originally posted by Late_Cretaceous
"I always thought the structural similarities were a pretty obvious thing. I've accepted some kind of common descent since I first understood how a cat's hind legs are jointed. The joints are spaced differently from ours, but they're the same joints."

I once pointed this out to a creationist in a verbal "debate", to which his reply was "why are a dog's knees backwards". When I said that was the dog's heel, he dismissed me and the whole debate .

ROFL! That was exactly the insight I was referring to.

For those who have canine or feline pets:

The "hip" is the joint up near the spine inside the animal.

The "knee" is the joint right near where the leg appears to leave the body.

The "heel" is the joint right before the foot (as it should be)

Compare your bones to your pet's. (If it's a cat, expect to get bit during the part where you're feeling the upper leg bones.)

Now let's try the front legs: Shoulder is inside the animal, elbow is right at the edge of the torso, wrist is fairly far up, fingers are very short.

Once again: Same basic bone structure. For all four limbs. (You may get bit during this part too.)

Now, look at the *differences*. Now try moving on all fours. Wouldn't it be neat if the front limbs were a bit longer, and if the rear ones were a bit shorter? Play around for a bit figuring out how to make yourself a good quadruped. Now look again at the cat.

Gosh. It's almost as if we started from the same design, and went in different directions, occasionally moving a joint an inch or two, but never really changing the basic jointing, even though we would probably be much better off with more flexible knees.

 

[Morat]

  I once  had a guy swear some dogs had feathers between their toes. Admittedly, in some breeds, you get a lot of fur between toes (especially dogs bred for swimming), and it looks vaguely like feathers if you're drunk...

  It just goes to show: People don't really look.

 

 

[seebs]

Wow.

That's amazing.

BTW, on a related note: "declawing" cats consists of, essentially, trimming their toes at the equivalent of the first knuckle. Having learned this, I don't plan to do it to any of my cats in the future. (Poor stokes. All no toes.)

 

[Cantuar]

I once had a guy swear some dogs had feathers between their toes.

Oh, dear - sounds like someone who doesn't understand the term "feathering" in a canine context. This is the problem with dealing with literalists. I remember once coming very close to telling someone that the missing link was a red herring until I realised the potential dangers of literalism.

 

[Jerry Smith]

I remember once coming very close to telling someone that the missing link was a red herring until I realised the potential dangers of literalism.

ROFL!!!!