... and the most persuasive explanation I've seen for the popularity of quote-mining is as you say - an appeal to authority. An odd thing about these appeals is that the typical creationist ... don't seem to care much if the Authority appealed to is terribly relevant: ...
It is used because it agrees with the worldview of the quoter, not so much as an appeal to authority, but as confirmation of one's views. Most users of such quotes mines don't see this as a logical fallacy for this reason.
It's confirmation bias, and it doesn't matter if the author also contradicts it, the point is made that is in agreement with the worldview.
I think, with no proof at all, that the practice grew out of the Sunday School teaching method of memorizing selected Bible verses.
I think its more pervasive that that. It has to do with how people are taught things in general, with the well known parent phrase "because I said so" establishing behavior based on authority.
We could also point out that kids are also taught to ignore contradictory information by the same process, so cognitive dissonance is dealt with by using authority to overwhelm the contradictions.
We could also point out that rote learning is frequently taught in public schools (in 1492 Columbus sailed the ocean blue...), rather than understanding and logical analysis.
In other words, the fundamentalists don't necessarily come to this behavior due to their faiths, they've been taught this behavior independently, and have trouble understanding that this is a false approach to learning. I've seen atheists make similar arguments.
Evolutionists have already embarassed themselves with the coelacanth first saying that its lobed fins were used for walking until a live coelacanth was found that showed that these fins were definatly used for swimming.
Is this this best you can do? Point to an error made over fifty years ago? An error corrected, not by creationists, but by the scientists themselves? Science continually corrects its errors. Creationism does not.
Actually Arphy's comment is false - evolutionists did not say that the lobbed fins were used for walking, instead what they did was recognize homologous formations in the bone structure of the fins that matches that found in tetrapods, thus it was evidence for possible common ancestry of tetrapods from lobbed fin fish, of which coelacanth was a likely (then) possibility.
They first appeared in the fossil record in the Middle Devonian. Prehistoric species of coelacanth lived in many bodies of water in Late Paleozoic and Mesozoic times.
Coelacanths are lobe-finned fish with the pectoral and anal fins on fleshy stalks supported by bones, and the tail or caudal fin diphycercal (divided into three lobes), the middle one of which also includes a continuation of the notochord. Coelacanths have modified cosmoid scales, which are thinner than true cosmoid scales. Coelacanths also have a special electroreceptive device called a rostral organ in the front of the skull, which probably helps in prey detection. The small device also could help the balance of the fish, as echolocation could be a factor in the way this fish moves.
Other fish do not have the bone structure of lobbed fin fish, and thus are not homologous with tetrapods in that regard.
quote:From the time of the first fossil coelacanth named in 1839 by Louis Agassiz, the fish was a curiosity because of its apparent "proto legs" and the protruding tab on its tail the posterior or epicaudal fin.
The most that was ever claimed was that it was possible that these fins could have been used in a walking style motion along the coean bottom, a mode of operation we see with several existing species of fish. Some modern fish have evolved the ability to pull themselves out of water using their lobbed fins, but this is not walking.
Perhaps one of the most striking differences between fishes and amphibians — at least in the Devonian — was in the structure of the limbs. This makes sense because a fin used to paddle a neutrally-buoyant fish about in water is not capable of lifting and hauling this same fish about on dry land.
Note the homologies in the bone structure in the picture, homologies that also occur in coelacanths. Coelacanths are now regarded as cousins of the common ancestor to tetrapods.