Cornelius Hunter
Posts: 11
Joined: Jan. 2007
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Addressing the second part of Deadman's post:
| Quote (deadman_932 @ Feb. 05 2007,14:59) | Actually, it's not subjective or circular , and that is a misrepresentation of what I did say. I specifically noted that the flying squirrel and phalanger don't have structurally identical patagium...BUT their pentadactyly IS precisely the same.
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Why do you find it to be significant that the pentadactyl pattern is “precisely the same”? Are you claiming that the homology evidential claim would falter if this were not the case?
| Quote (deadman_932 @ Feb. 05 2007,14:59) | Further, I am in fact arguing that skin attachments and increased skin area in between attachments IS in fact easier for a strain of animals to change than basic bone structure...
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OK, good...
| Quote (deadman_932 @ Feb. 05 2007,14:59) | why do I say that? Because we have no large-scale evidence of septadactyly or octadactyly to point to. We have only pentadactyl mammals on the planet.
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Why is it important that septadactyly or octadactyly is not found in “large-scale”? And why is it important that mammals have only pentadactyl?
| Quote (deadman_932 @ Feb. 05 2007,14:59) | Further, we can conduct experiments showing that basic bauplan features are far less susceptible to mutation and alteration than skin attachments to bone, especially under selection by the environment and reproductive success.
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So is this then an evidential problem for evolution? For if basic baupan is hard to evolve, then how did evolution create such a menagerie? On the one hand, you want to argue that homologies such as the pentadactyl pattern are powerful evidence because, after all, it is so very difficult to modify. Therefore, when we observe it in different species, this must be evidence that the design was inherited from a common ancestor. But this is a curious argument to make when, on the other hand, we are saying evolution not only created the pentadactyl pattern, but very many other bauplan features over time.
| Quote (deadman_932 @ Feb. 05 2007,14:59) | 1 .Isn't the very claim that "theory-laden" observations are somehow "less than" or inferior to "theory-UNladen" observations...itself a theory-laden hypothesis? How does your view qualify as "better?" when it is also laden with theory?
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Trust me, your evidential argument for a theory is going to be stronger if it does not entail conclusions that flow from the theory itself. If you disagree, then so be it. But I’m looking for justifications that are free of such theory laden-ness. More below.
| Quote (deadman_932 @ Feb. 05 2007,14:59) | can you please explain your association with DI?
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I am a Fellow, which is a fairly loose association. I need not agree with DI on anything in particular, and vice versa. I have not been given the secret handshake.
| Quote (deadman_932 @ Feb. 05 2007,14:59) | 2. How did you determine that characters were "equal or greater " in similarity when there are no justifications at all ( in your mind) of making such a claim?
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Look here at the pentadactyl patterns:
http://en.wikipedia.org/wiki/Image:Evolution_pl.png#filelinks
Then look here at thylacine:
http://en.wikipedia.org/wiki/Thylacine
and see the similarities with Canis lupus:
| Quote | | The Thylacine showed many similarities to the members of the Canidae (dog) family of the Northern Hemisphere: sharp teeth, powerful jaws, raised heels and the same general body form. This is an example of convergent evolution. The skulls of the Thylacine (left) and the Timber Wolf, Canis lupus, are almost identical although the species are unrelated. |
Are you saying similarities between thylacines and wolves are insubstantial compared to the bat and horse pentadactyl designs?
| Quote (deadman_932 @ Feb. 05 2007,14:59) | I'd also like you to show me an example of scientific observation that is not theory-laden.
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It is not a matter of whether or not theory-free observations are possible. Perhaps all observations are theory-laden, but the theory-laden-ness need not be particular to the theory one is trying to advocate. Here’s an example. An astronomer makes observations of distant galaxies and constructs a new theory about galaxies. His observations are laden with assumptions about the universality of natural laws, for instance. But such assumptions are generally accepted by his audience, though his new theory is not. The theory-laden-ness of his observations is not the problem. Rather, his new theory does not fit all the observations very well, though no one objects to the theory-laden-ness of the observations.
On the other hand, let’s look at an evolution example. An evolutionist uses DNA sequence data to construct phylogenies. First, the data are processed to cull homologous sequences, thus rejecting differences. Then the analysis is rerun several times to hone the results, and remaining outliers are explained as a consequence hypothetical evolutionary scenarios. The results are published, and later become strong evidence for evolution and we use them to confirm our flimsy conclusions.
| Quote (deadman_932 @ Feb. 05 2007,14:59) | 3. You have steadfastly refused even up to now, to simply enumerate what these characters ARE that you wish to compare to pentadactyly .
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Again, look here at the pentadactyl patterns:
http://en.wikipedia.org/wiki/Image:Evolution_pl.png#filelinks
Then look here at thylacine:
http://en.wikipedia.org/wiki/Thylacine
and see the similarities with Canis lupus:
| Quote | | The Thylacine showed many similarities to the members of the Canidae (dog) family of the Northern Hemisphere: sharp teeth, powerful jaws, raised heels and the same general body form. This is an example of convergent evolution. The skulls of the Thylacine (left) and the Timber Wolf, Canis lupus, are almost identical although the species are unrelated. |
And answer this question: If species can exhibit similarities such as those in thylacines and wolves that are not due to common descent, then why must similarities such as the pentadactyl pattern be due to common descent? Do not merely explain the data according to evolution. This does not explain why it is powerful evidence. And do not presuppose evolution in your answer.
| Quote (deadman_932 @ Feb. 05 2007,14:59) | When you did mention the patagium in Phalangers/Flying Squirrels, you seemed to ignore the evidence that shows that there is very little underlying structural similarity in the two adaptations other than "skin stretched between fore- and hindfeet." which doesn't have the same weight as pentadactyly that can be seen in all mammals today, in the fossil record of mammals and beyond and that has relatively well-known genetic and developmental evidence -- all of which you will of course, "invalidate" by saying it is "theory laden"
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But the genetic and developmental evidence need not be theory laden (that is, in ways that are peculiar to evolutionary theory). That’s the key.
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