Jim Bell wrote:
>Glenn is arguing that to expect a continuum is "unreasonable." But Stanley,
>and all other evolutionists, would never make such an argument.That is why
>Glenn provided no citations to back up his remarkable thesis.
Last week I bought a book at my favorite local used book store entitled
Developmental Biology by Scott F. Gilbert (Sunderland, Mass.: Sinauer
Associates, Inc., 1991). I have not had time to read the book yet, but late
last night after Jim's challenge that this could not be documented, I looked
at the last chapter of this book. Gilbert says,
"In many ways, the phenotypes of the homeotic delections resemble the
postulated earlier stages of _Drosphila_ evolution. _Drosphila, a two-winged
(dipteran) fly, is thought to have arisen from normal four-winged insects
(pterygotes). This condition can be acheived by deleting the _Ubx_ portion
of the bithorax complex. Winged insects are thought to have evolved from
nonwinged (apterygote) insects. This situation is mimicked by the deletion
of the _Antennapedia_ gene, in whose absence all the thorax develops like the
wingless first thoracic segment. The apterygote insects are believed to have
arisen from myriapod-like creature (millipedes, centipedes), a situation
similar to the phenotype generated when the entire bithorax complex is
missing and the entire posterior of the embyro develops like a legged thorax
segment. Finally, if both sets of homeotic genes (the _Antennapedia_ and
_Bithorax_ complexes) are removed, the result is a condition similar to that
of the most primitive known arthropods, the onychophorans. As Raff and
Kaufman (1983) have said, "Thus, by sequential deletion of a relatively small
amount of genetic material we have managed to traverse a rather large amount
of evolutionary ground.""( p. 835-836)
Two observations: 1) If by the addition of new parts to the homeotic genes,
major morphological change occurs, then the constant claims by
anti-evolutionists for more and more transitional forms may be based on an
outdated view of genetics
2) This type of small "genomic" change = large phenotype change, is exactly
what is seen in those programs I wrote and made available to the
reflectorites.
glenn