Talk:Counterexamples to Evolution
The neck of the giraffe is a great counterexample, BrianCo!--Aschlafly 13:54, 23 November 2007 (EST)
- How so? I don't get it. In what way does the giraffe's neck say anything one way or the other about evolution? Humblpi 04:35, 15 February 2008 (EST)
Ummm...this is a dangerous topic to take up, but it's my area of expertise, so what the hey. Most, if not all of the examples in the article can be explained from an evolutionary standpoint.
1) Beautiful autumn foliage is an adaptive response of plants to conserve energy during relatively low-production months. They actually resorb energy during fall, so the cost-benefit analysis works in their favor. This is one reason there is no seasonal loss of foliage in the tropics, which have a near-constant energy pool.
2) Molecular evidence places whales and dolphins in the same clade as cows (Artiodactyla). The presence of vestigal limbs is very strong evidence for this theory, as well.
3) There is a plausible pathway to the development of the eye, including numerous intermediate structures that were much simpler and less effective. Indeed, the vertebrate eye is quite flawed (blind spot, image inversion), as one of the tenets of evolution would predict (the idea that natural selection can function only on existing structures).
4) I would be willing to bet that there is an explanation for the evolution of blood clotting, but I need to do some book work first. Off the top of my head, I can't think of one, so in the interest of vigorous science, I concede that point for now.
5) The swarming of jellyfish is a response to an influx of planktonic life brought on by the full moon...the predators follow the prey.
6) The timing of cicada species has to do with the availability of reliable energy sources and reliable mates. The somewhat arbitrary time periods highlight the underlying randomness of mutations.
7) I'm not sure whether point seven is referring to the ability of birds and butterflies to navigate, or their migrative lifestyle, but there is an explanation for both. Migration is an adaptive trait to allow exploitation of otherwise inhospitable regions, and the navigative abilities evolved as a response. Humans and other mammals actually possess a rudimentary ability to detect the magnetic field...a holdover from our own migratory days.
8) The neck of giraffes is a textbook example of sexual selection.
9) The gaps in the fossil record can be explained by the sheer difficulty of creating fossils. Probability argues against having fossils of everything.
10) Feathers could have evolved from scales, and there is molecular evidence for this.
11) Point eleven simply makes no sense...I have never heard anything like this concept in my years of studying biology. I think it may just be poorly written, but I can't understand the point well enough to refute it.
I have sources (often many) for all of the above, but I have to rush to rehearsal now, so I'll add those later.--Thinker 16:47, 24 October 2008 (EDT)
- I think lists like this are simplistic, but here's some responses.
- "Beatiful autumn foliage is an adaptive response of plants to conserve energy during relatively low-production months" is story-telling. It doesn't explain how evolution could have come up with the idea. The rest of your point applies equally well to creation: God designed it to have a good cost-benefit ratio.
- Being in the same clade does not mean that there is an identifiable ancestor. Vestigial organs are due to a degradation, whereas microbes-to-man evolution requires innovation.
- The "plausible pathway" explanations are not plausible at all, taking great leaps in complexity (e.g. starting off with an extremely complex "light-sensitive spot". The vertebrate eye is not a flawed design at all. What's wrong with image inversion? That's a natural consequence of using a lens. As for the blind spot...
Ophthalmologist Peter Gurney gives a detailed response to the question ‘Is the inverted retina really “bad design”?’ He addresses the claim that the blind spot is bad design, by pointing out that the blind spot occupies only 0.25% of the visual field, and is far (15°) from the visual axis so that the visual acuity of the region is only about 15% of the foveola, the most sensitive area of the retina right on the visual axis. So the alleged defect is only theoretical, not practical. The blind spot is not considered handicap enough to stop a one-eyed person from driving a private motor vehicle.
- No comment.
- That makes sense. When you back that up with a source, I'll remove that one.
- The first part about energy and mates doesn't appear to explain it at all. The second part about mutations is story-telling.
- As for No. 1.
- Selection only selects from something that is already there. The question evolution has to answer is, how did it get there in the first place?
- That's an ad hoc rationalisation. It doesn't explain why the gaps are so systematic between different basic kinds of creatures.
- What molecular evidence? Molecularly, they are quite different.
- I agree that it makes no sense. I'll remove that one.
- Philip J. Rayment 00:51, 25 October 2008 (EDT)
- P.S. you had a typo in your first point. I wouldn't mention it except that I know you are fussy about such things!
Before responding, let me establish one thing that I should have said much earlier. My refutation of these points is not intended to prove evolution or disprove any "competing" theory. My goal is only to show that evolution can explain how these things came to be, and thus that they cannot be used as examples of failures in evolutionary theory.
Another related disclaimer: my claims are made from a background of evolutionary biology, so the reader should feel free to mentally insert "according to evolutionary theory" when appropriate.
I would first like to take these point by point as concisely as possible.
1) All origins theory is story-telling. The burden of proof is then upon the story teller to show that their explanation is plausible, and the different camps go about this in different ways. Evolutionary biologists do so by establishing a possible mechanism and doing controlled field studies to see if that mechanism actually works in the way we expect it to. If it does, then it's plausible enough to serve as an explanation, and more importantly, it can be used as a predictive tool. And that's all evolution really cares about...whether or not it happened is really irrelevant to our predictive capability. The fossil record (ie history) comes into play only when something is unexpected, because it shows us that our tool may be flawed and we need to fix it, or maybe get a new one (if you pardon the analogy).
2) Being in the same clade does imply a common ancestor in the same way that being in the same human family implies a relationship. To continue the analogy, assume for a minute that we have two siblings separated at birth. They think they are related, and a DNA test shows that they are, but they have no proof of a common parent without their actual living parents. However, the chance of common ancestry is high enough that there is no reason to reject the assumption (by the way, the analogy is flawed, but it captures the essence of scientific proof: assumptions based on plausible possibilities, based on past research and questioned more intensively when contrary evidence comes to light there is no such thing as certainty in science).
3) I will try to find a good copy of the proposed pathway for the development of the eye, but I know that there is no implausible leap in complexity over the hundred or so proposed structures in the lineage. But keep in mind, as I mentioned in 1, just because evolution can explain something a certain way doesn't mean it happened that way...biologists are constantly redoing our own version of history. Rather, I intend merely to show that these points are not evidence against biology. This one will have to wait until Monday, when the library is unlocked.
4) Is outside my area of expertise, and I will not mock those who know what they're talking about by bungling up an explanation here.
5) Sources for 5:a) Hickman et. al., Integrated Principles of Zoology, 13th ed. 2006. McGraw-Hill publishing, Boston, MA b) Solomon et al., Biology, 6th ed. 2005, Thomson-Brooks/Cole, Belmont, CA c) numerous lectures and individual observation...not a source per se, but they at least serve to tell that I'm not making it up.
The fact that those are all biology texts should give a critical thinker pause, but again remember that I merely want to refute these points as evidence against evolution, not prove evolution itself.
6) I actually recieved another explanation from another CP member that does a better job explaining it, so I'm going to use that one and throw out my own esoteric and very involved explanation. Many predators reproduce in regular intervals. 13 and 17 are prime numbers, and so are not divisible by any other number. This means that the predators are not able to sync their reproductive cycle with that of their prey. It's an adaptive function, but that explanation serves equally well for both evolution and ID. It does, however, show that evolution is able to explain that point.
7) Once again, I assert that all origins theories are story-telling and that that argument doesn't hold weight when applied across the board. The fact is that the explanation I provided is plausible and there is evidence to support that it happened (just to name one: Larkin et. al. "Evidence for widely dispersed birds migrating together at night", Journal of Integrative and Comparative Biology, 48:1)
8) The neck of the giraffe was already there as part of the basic chordate body plan (the origin of that plan is still hotly debated in comparative biology, and there are three or four very good theories that can explain the evidence). All traits exist in a normal distribution; that is, among the ancestral giraffe population, some individuals had longer necks. Male giraffes compete for mates, and those with longer necks are more effective competitors (they win more fights), thus sexual selection selected those individuals with longer necks, resulting in a textbook example of sexual directional selection (Kardong et al. Vertebrates, 4th ed. McGraw Hill publishing, Boston, MA, 2006). Evolution would be in trouble if giraffes didn't have the same number of neck bones as all other chordates...it couldn't explain that.
9) Let me change my tack, then, because my previous argument does seem rather ad hoc. Instead, I will refer to my analogy from 2: lack of an ancestor in the records does not imply that one didn't exist if such existence is highly likely. Moreover, one of the ways to test evolution is the prediction of intermediate forms, and these hypotheses are confirmed with the discovery of said intermediates. I will also say that the gaps in the record are constantly being filled in: a fossil called Diplognathus was recently discovered which confirmed a somewhat odd explanation for the derivation of ear bones (that's just one example). (Kardong et al. Vertebrates, 4th ed. McGraw Hill publishing, Boston, MA, 2006)
10) The molecular evidence of which I speak refers to the nuclear material found within the cells creating scales and feathers, and within the proteins which make up the scales and feathers themselves. For starters, they are molecularly identical, both being composed primarily of keratin. Furthermore, all versions of a different protein have very slight variations, both in terms of the protein themselves and in the DNA which codes for them. The sheer size of both molecules mean that the chance of a similar variation occuring by chance is negligible, so similarities in variation imply common ancestry (similar to the "twins separated at birth" analogy). The variations in keratin are very similar between birds and reptiles, implying a common descent (Glenn et. al. "Evolutionary relationships among copies of beta keratin genes from several avian and reptilian orders" Journal of Integrative and Comparative Biology, 48:4)
And I think that is more than enough talk on that for now...I need a break. All I will do is close with saying once again that I do not claim these are proofs of evolution or "disproofs" of other theories. I merely claim that the specific points in the article can be explained plausibly by evolutionary theory and thus can't be used as counterexamples. --Thinker 12:34, 25 October 2008 (EDT)
- Your comments above range from concepts like "there must be an evolutionary explanation" to "the burden of proof is on someone else."
- The point here is simple: one counterexample disproves the theory of evolution. Accept that logical truth, or go no further and admit that you will adhere to evolution no matter what logic dictates.
- It only takes one counterexample. Number one in the list -- beautiful autumn foliage -- is enough. The foliage existed before man does, and beauty does not help the trees in the slightest. The theory of evolution is confounded by the beauty, and the best it can say is it happened by chance. But such beauty does not happen by chance.--Aschlafly 15:39, 25 October 2008 (EDT)