In a message dated 8/23/99 4:28:24 PM Central Daylight Time,
[log in to unmask] writes:
> Assuming that by "do not believe" you mean "am not convinced" I guess we
> differ on what "observed" means.
Yes, this is what I mean (Pardon the colloquial expression). Apparently we
do have differing views as to what constitutes an observation.
> There are plenty of examples of continuous
> stratigraphic sequences showing divergence of species, for example in
> foraminifera in deepsea cores and in diatoms from cores in lakes. Here's an
> example in mollusk. In the Miocene Pannonian lake basin in Hungary, Muller
> & Magyar (1991, Acta Palaeontologica Polonica 36:353-372) found a gradual
> transition over time between species of cockles that were previously placed
> in two different genera in different subfamilies. The lineage starts with
> Lymnocardium decorum ponticum and leads to the genus Prosodacnomya.
>
> Do you consider this kind of change through a stratigraphic sequence to be
> an observation or an inference?
I cannot intelligently comment on the above based simply on your comments. I
am more than willing to look at this study before forming an opinion. I will
check with the geology department at the local university in an attempt to
locate this paper. If it is a rare or obscure paper not readily available
could you or someone kindly provide a photocopy. I am curious and I really
enjoy a challenge.
> To me it is an observation. Isn't this the
> kind of evidence that you request in the case of Archaeopteryx? The lack of
> known intermediates in a particular case doesn't mean that intermediates
> haven't been found in other cases.
In agreement with Ross' recent post, intermediates appear to be lacking
across the board; a fact acknowledged by several prominent evolutionists.
> >> What if something evolved entirely by macroevolution? Blammo, in one
> giant
> >> mutation, something vastly different appeared. [stuff deleted]
> >
> >Mutations generally do not improve a species.
>
> I didn't say mutations improve species. I don't think they do; they merely
> make them different. I'm saying, suppose that incredibly rare, one in a
> quadrillion mutation occurred, and something extremely different from its
> parents appear and somehow thrived. Here's a real example:
>
> Van Valen & Maiorana (1991, Evolutionary Theory 10:71-74) named the human
> cell culture line known as HeLa cells as a new family, genus and species:
> Helacytidae, Helacyton gartleri. These amoeboid cells are derived from a
> carcinoma in Henrietta Lacks in 1951. They have somehow been immortalized
> so that they can keep dividing, rather than dying after 50 or so divisions
> as do most cell culture lines. The number and organization of chromosomes
> is different than in humans. HeLa cells invade other tisse cultures, and
> have become pest in the laboratory, expanding their range from North
> America to other continents. They can no longer interbreed with their
> parent species. (Human giving rise to amoeba--sounds like something that
> happened in Art Weil's basement.)
How interesting! Now we are evolving into simpler life forms. Sounds a bit
familiar; kind of like reincarnation. It must have been bad karma. :)
> If an example of a change of a similar order of magnitude (phylum to
> phylum) could be found outside the laboratory (morphology saying one thing,
> genetics saying another), would that be evidence of macroevolution?
I restate my position. Observable (not inferred) evidence of one phylum
tranforming into a new or different phylum would be persuasive and worthy of
a second look. I await such a phenomenon.
Doug Shelton
Alabama Malacological Research Center
2370-G Hillcrest Road #236
Mobile, AL 36695 USA
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