Actually the article from talk origins we all need to check is this one:
http://www.talkorigins.org/faqs/abioprob.html
And no, I do not think the probability is zero.
Not quite. It was eventually rejected because no one could duplicate Harrison’s results. Nevertheless, he was essentially given a “free ride” because of his status as a respected scientist, so no one even questioned his results until Kettlewell (which is not to say that the same might not have happened with Kettlewell). From here:
After researching this topic, it seems that the real truth is that the whole peppered moth story is muddled with improper experiments, so it really is rather difficult to work out what, exactly, was going on. I shall, therefore, retract my earlier statements regarding the use of these moths as examples of natural selection at work. And I fully agree that until someone conducts a more thorough investigation, which should also look into the possibility of Harrison’s induction, that this example should not be used as evidence for natural selection in current textbooks.
It should, perhaps, be included as a rather interesting tale of the scientific process at work, however.
My point in referencing the article is that there were observed changes in morphology due to environmental changes. Whether it was due to predation, or to sulphur dioxide, there was an increase in the darker allele and the ‘survivability’ of the lighter allele decreased. With the ‘change back’ in environmental factors there was a corresponding ‘change back’ in allele frequency. Yes, it is clear that the Kettlewell experimentation was flawed, but this is not a ‘chink in the armor’ rather yet another example of how the Scientific Method allows us to examine all aspects of the process (including folks trying to carry out the process).
This is the crux of the argument - One can pick apart an experiment ad infinitum, but it does not change the fact that Evolutionary Theory is indeed supported by the observations of the Peppered Moth.
GIGObuster
I suppose it’s a matter of taste, but since Ian makes essentially the same claim as I do, then it’s hard to find fault with the fundamental message…
Nor do I.
CheapBastid,
Well, first of all, I didn’t assert that the Peppered Moth observations failed to support the theory of evolution, only that it was not obvious that it was a good example of natural selection.
However, the only obvious support of evolution is that frequency of the alleles controlling coloration changed. How they changed and why they changed are not so clear.
In light of this, not many evolutionists would use this example as a banner of triumph. Moreover, not many creationists would find this conclusion disturbing in the least.
The sad thing, to me, is that everyone seems to be overlooking the most obvious evidence for natural selection in this example… the fact that the natural resting place for the Peppered Moth was on the underside of branches in the canopy of trees. How did this come to be, if not through some process of natural selection? Perhaps some creationists might claim that it is in the ten commandments for moths (thou shalt not rest on the sides of tree trunks), but it seems to me that more than likely, moths that didn’t have a natural fondness for upsidedowness probably got gobbled up.
I’m glad to find you guys. I have some questions, but I have to ask for the respnses to be in the form of a question. No, I just need them to be in a form I can understand. I do know “allele”, but when we get to “morphology” and beyond, my eyes are glazing a bit.
I’m looking to be a HS chem teacher, so these things will come up, I know. Most kids in chem, especially honors chem, are taking Bio concurrently.
I don’t mind if some people want to only address certain parts.
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Is there a summary (just a couple paragraphs will do) on which guy did which part of the analysis with the moths, and what the current conclusion is? I think I get the main point (good one, ACON), but I’d like to have it in a memorable form that I can explain to 10th graders.
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Back to the giraffes for a moment. In general, I get the idea of the advantage of being long-necked. What about the babies that are weaned? I’ll take a shot myself: The parents help feed them. Most mammals have a nuturing nature past weaning, and I bet giraffes do too.
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How solid is this idea that ribosomes are incorporated bacteria?
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What’s with this mention of a predicted whale fossil? If we can predict things, isn’t that tremendous evidence for the theory being used?
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Is Miller’s zap-it experiment being seen as possibly irrelevent? I just had that mentioned in class (admittedly, not a life-science one, and not at a good school).
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Ok, now the biggie. I’ve been in a long argument with a psuedo-creationist friend, and he insists on on using the phrase “classic evolution” to mean a necessarily Godless process, period. I said that even Darwin didn’t mean that, but he says that’s all you ever hear about in school, so that’s what it’s come to mean.
Can’t we agree with my other friend that all the evidence mentioned doesn’t begin to address a possible “directing” or whatever? Assuming that the “directing” doesn’t involve too big a step (or even if it does, maybe), there’s not some sort of “directed step fingerprint” in the fossils. If you want to believe that this is all part of a grand design, or even part of a directed process (right?) you can, as long as you agree that evidence is evidence and don’t go off half cocked, listening to people with law degrees more than those with geology or paleontology doctorates.
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Is there some sort of summary that I can remember three months from now how DNA analysis points to a commonality among life forms? Is it that DNA and RNA are common among them, or is there more? It seems to be implied that there’s more.
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(Last one) I assume someone here is familiare with Michael Behe’s “Darwin’s Black Box”. What is the (I assume rather devastating) response to his assertion that there are irreducable processes that imply some sort of (untracable) intervention? I think that even if he’s mostly full of junk, doesn’t he have a point that most textbooks make no attempt to explain a process by which evolution might have happened on a molecular level?
Or, is this an admitted area of small knowledge as of yet, requiring him to just shut up and wait? I realize we can’t know everything just because we want to.
Gee, one could write a book about any of those questions. I’ll try to address a few.
Yes.
Miller’s experiemnt is still relevant, although the field has moved on a lot since then. The issue with creationists is more that the Miller-Urey experiment and the experiments done since then demonstrate the possibility of one step of a multi-step process, whereas creationists tend to demand proof of the actual occurence of a particular process. In other words, if you haven’t dumped some atoms into a beaker and produced a mouse, creationists claim it’s irrelevent. Of course, they’ve got you coming and going; if you were to dump some atoms into a beaker and produce a mouse, to a creationist that would be proof that intelligent intervention (the experimenter) is required.
I think most biologists would agree that the evidence and theory do not preclude direction or intervention by some divine power. However, I am convinced that the majority of biologists would agree that there is no evidence that does suggest that such intervention has taken place or is taking place. Sorry, no cite; there just doesn’t seem to be a reasonable survey of biologists on this issue.
There’s more. There’s a pattern of degrees of similarity that almost exactly matches the “nested hierarchy” pattern that was independently developed by analysis of morphology from the fossil record and living organisms. I don’t have any great links, but Evidence for Evolution, Re: Do it yourself chimp-human DNA comparisons, Re: Evolution proof?, and Evidence for Evolution may be interesting.
There have been many responses to DBB, and I and many others find them devastating. A fundamental problem is defining “function” … on first glance its meaning seems obvious, but when you try to nail it down it’s a surprisingly slippery concept. There doesn’t seem to be much going on in this area; Behe’s concentrating on the lecture circuit.
I don’t know what the textbooks say, so I can’t comment on that.
All the examples Behe produced as possibly “irreducibly complex” have been shown to have a plausible evolutionary origin, and in some cases an almost certainly evolutionary origin (e.g. see A Delicate Balance and Evolution of the Bacterial Flagella). Note that Behe never claims that any particular biochemical system is irreducibly complex. Note also that his claims of lack of research into the origin of such systems are incorrect (Some published works on biochemical evolution).
Biochemical systems have been produced by evolutionary processes in the lab that appear to meet Behe’s definition of irreducible complexity. Behe’s response is typical of a creationist or “intelligent design” theorist; since an experimenter was within ten miles of the expeeriment, the result required intelligent intervention. See A True Acid Test.
Behe’s entire argument can be reduced to the classic argument from incredulity; he can’t imagine how it happened, therefore it couldn’t have happened.
Further reading: Design on the Defensive, Behe’s Empty Box, A Biochemist’s Response to “The Biochemical Challenge to Evolution”, Darwin’s Black Box: Irreducible Complexity or Irreproducible Irreducibility?, and How Can Evolution Cause Irreducibly Complex Systems?
Well, I’ll try to punch through those links some time. Thanks. Anyone else care to address the rest? Oh, and “Yes” isn’t much information on what was predicted about the whale fossils.
I’m not exactly sure what you are asking here. Baby giraffes stand 6’ at birth, and reach 10’ by the time they are one year old. They also tend to suckle for up to a year, though they do sample plant matter within their reach during that time. By the time they are fully weaned, they are able to dine on foliage above the reach of the typical savannah browser or grazer (only the elephant can compete, though giraffes typically go for acacias, whereas elephants are rather more indiscriminate).
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To add to what JonF said about this, “classic evolution” is godless only in the sense that it does not require divine involvement (unlike, of course, any form of creationism). It does not, however, deny God. This is a distinction which is lost on many creationists. In essence, whether God exists or not, evolutionary theories are sound. However, for any form of creationism to hold, God must exist.
Yup. The “Yes” was in response to “If we can predict things, isn’t that tremendous evidence for the theory being used?”. I’m not sufficiently conversant with the recent developments in whale evolution theory to discuss the first question.
See here for a discussion on this issue. However, note that there is currently some debate as to whether whales are truly descended from mesonychians (as originally thought), or are more closely related to the ungulates. See here for a discussion on that topic.
There’s less debate than there used to be. Re: whales pig out
Cardinal,
My vote would not to mention this at all as a topic of study, unless it’s a study about the difficulties of the scientific method. There currently is no conclusion, only speculation.
Tricky question. No doubt, that this fossil evidence is of significant importance. I have doubts about significance of the predictive nature of this example, though. I have a slight bias - my domain is that of “harder” sciences. When I compare the predictive power of the Theory of Relativity that can always be shown to hold versus the Theory of Evolution which, by the very nature of the evidence, cannot always demonstrate alignment and has some inherent subjectivity, I tend to shy away from phrases like “tremendous evidence for the theory”. I’m sure others on this board are ready to pronounce it Q.E.D…
It is absolutely relevant. There may be questions about the particular composition of the early Earth atmosphere, but it opens the door to plausible theories about how amino acids could be formed. Even in the predominantly Carbon Dioxide and Nitrogen atmosphere theory, amino acids can form and conversely in the Hydrogen, Methane, and Ammonia atmosphere of Miller-Ulrey, not all of the necessary amino acids will form. Both theories require more - other gases, different chemical processes, etc…
Human belief systems are a spectrum. At one end of the spectrum you have creationists who are very dogmatic about the origins of man. On the other end of the spectrum you have atheistic evolutionists who are very dogmatic about the origins of man. There’s a lot of room in the middle for both God and evolution…
Careful not to assume that a paleontologist will be more objective and more capable (scientifically) than a lawyer. In general, this may be true, but there are exceptions to both rules (i.e. evolution saavy lawyers and lame paleontologists)
http://www.talkorigins is your friend. It’s a good starting point for many of the questions you are asking.
This, coupled with your earlier “bullshit” comment on the testability of common descent, indicates that you may not have a firm understanding of how “historical sciences” work. There is no such thing as a mathematically-rigorous level proof in such sciences; I can assure you that no one on this board who has any idea what they are talking about would make any “Q.E.D.” pronouncements with respect to whale evolution, or anything else in the field. Paleontology, as an exmaple, requires a great deal of deductive reasoning - moreso, certainly, than, say chemistry or physics. However, the reasoning is no less valid than that used in forensics, as another “historical” example. The point is to piece together the past from various bits of information, despite the fact that there were no eyewitnesses. Tests in evolution do not necessarily require any sort of labwork (various theories involving genetics tend to lend themselves more easily to this sort of thing than, say, the theory of common descent, or the evolution of whales). Often, a successful test is corroboration from a separate area of study. An example is the corroboration between the fossil record, morphological analysis, and genetic analysis for common descent (to continue to use the example raised earlier). Each of these taken unto itself does not make for a very convincing case. All of them taken into account makes a much better case. And, as with the “hard” sciences, if evidence arises which invalidates a theory, then it gets adjusted or rejected, depending on the nature of the evidence.
Similarly, with the whale, it’s fairly easy to predict what a land-based precursor to an aquatic mammal should look like, or what features we should expect to see if such a transition did occur. Ambulocetus matched these predictions quite well.
Each new piece of evidence does not “prove” anything. Rather, each new piece builds upon an existing foundation, and works to provide a strong case. For whales, the case very strongly points to artiodactyl ancestors.
You might be interested in The Peppered Moth - An Update which IMHO summarizes the current mainstream scientific thinking.
Finch,
That was precisely my point and merely my point. In fact, you said it much more eloquently than I. I was simply trying to make a comparative analysis between two types of sciences.
So far, I’ve not found this to be true. I point to one minor example of dogmatism, in your own words:
Even after admitting that Kettlewell’s interpretation the Peppered Moth coloration analysis may not be valid, you proclaim Natural Selection as the driving force, but offer no proof or even a suggestion of what the selection pressures might have been. I’m not trying to get confrontational - just point out that the idealism of your words may not be entirely reflected in your behaviors.
Perhaps you missed this:
Clearly, when I made the initial pronouncement, I did not have all the facts (therefore, I fell under the classification of “one who does not know what he’s talking about”) about the peppered moth experiments. In my defense (sort of), the whole peppered moth thing was never even mentioned in any of the college-level evolution courses I took. Its use as an example seems to be limited to general bio courses.
However, I would like to point out that when I had done some more research, I found that my intial claim regarding the peppered moth as an example of natural selection was unfounded, and I retracted the claim.
You’re right and I retract my example and appologize for suggesting that you were/are less than objective in this matter.
That should be in the FAQ as an example of proper behavior.