mrh@cybvax0.UUCP (Mike Huybensz) (02/22/85)
References: I'm very impressed by the amount of work you've gone to, Paul. (Just how many hours did you spend on this anyhow?) And it is entertaining to see myself cited right after Gould and Eldridge. (Though on a matter of argument, rather than evolution.) However, I'm not greatly impressed by most of your arguments. (Some were sound, but many others dwelt on the individual trees so much that the forest was missed.) The most notable source of your arguments is the basic problem of describing details of a phylogeny. First, let's consider the question of lineage. Lineages of species must exist according to evolutionary theory. Identifying them is a non- trivial problem, because we didn't observe them. All we have is the spotty fossil record. Here is a useful analogy. Let's say I don't know my family tree, and I find a picture of someone unmistakably in my family (there is a strong family resemblance.) Is the picture of my father? My uncle? My much older cousin? Say I find some more pictures. I can then arrange them in a hypothetical family tree (network). But have I found all the pictures? If I haven't, I may have deductively assigned the wrong person as my father whose picture I haven't found yet. (I know I had a father....) The task in evolution is slightly simpler since there is usually only one "parent" instead of two. But there may be the same multitude of siblings. How do I know that a fossil species that I find isn't an uncle rather than a father to another species? That's why some people will say that evolutionary lineages cannot be reconstructed accurately. Because we are prone to make detail mistakes. However, the lineages exist. And the larger the scale you look on, the less important small details like which sibling was the parent become. "I don't care which McCoy was his daddy, we Hatfields still hate him!" It doesn't matter which (fill in the blank)pithecus we evolved from, we still evolved from ape-like ancestors. So, the "problem" of lineages, upon which you wax eloquent with many citations is one that is well known and understood. There is a systematist's philosophy particularly for dealing with this task, called cladism. Another source of your misunderstandings is the problem of at what branching point to declare that a subgroup begins. Assuming (for the moment) gradualism, at what exact point does a new species appear? The correct point is whatever we choose, because there is no clear-cut difference from generation to generation. Generally we choose a point where there is a gap, because that provides a convenient distinction. That is why there is a distinction between reptiles and birds: because there was a gap. When Archaeopteryx was found, it fitted somewhere in the gap. That's why some called it reptile and some called it bird. Now, of course, there are two gaps, on either side of Archaeopteryx. Perhaps not equal sizes. If we find another gap-filler, we will then have two new gaps. So, when creationists say "that's not a bird/reptile intermediate, that's a bird" they are saying the equivalent of "You're not a Hatfield, because your father was a McCoy" while not telling you that your grandmaw's maiden name was Hatfield before she married grandpaw McCoy. While citing patronymy (a mere naming convention), they are concealing descent. More after I reread... -- Mike Huybensz ...decvax!genrad!mit-eddie!cybvax0!mrh