Re: Scientific theory

Question: I understand you to imply that the definition of species involves any kind of "reproductive isolation." In your example, the isolation would be mechanical, not genetic. Presumably the definition would not include simple geographic isolation, even though geographic isolation is known to lead to new species. Correct?

Don

  ----- Original Message -----
  From: bivalve<mailto:bivalve@mail.davidson.alumlink.com>
  To: ASA<mailto:asa@calvin.edu>
  Sent: Monday, December 13, 2004 3:39 PM
  Subject: Re: Scientific theory

> And that kind of change is the sort of thing that these people have been told about and are interested in: "man from ape." Can you make dog variations seem relevant to someone who doesn't accept evolution? <

  It would probably help to have skeletons of various breeds to help visualize the magnitude of differences that have been created, since we are already familiar with and thus ignore the external variations. One aspect of particular relevance is the role of neoteny in both creation of certain dog breeds and of humans. Short-faced dog breeds resemble puppies of other breeds in their cranial proportions. Similarly, the relatively large brain to body ratio of humans is more similar to that of very young apes than adult apes.

  Another way in which dog variation may be brought to relevance is to point out that if we were to eliminate all the middle-sized dogs, there would be reproductive isolation between, e.g. chihuahuas and St. Bernards. This would create of separate species, something which is denied by some antievolutionists despite the many known examples.

      Dr. David Campbell
      Old Seashells
      University of Alabama
      Biodiversity & Systematics
      Dept. Biological Sciences
      Box 870345
      Tuscaloosa, AL 35487-0345 USA
      bivalve@mail.davidson.alumlink.com<mailto:bivalve@mail.davidson.alumlink.com>

  That is Uncle Joe, taken in the masonic regalia of a Grand Exalted Periwinkle of the Mystic Order of Whelks-P.G. Wodehouse, Romance at Droitgate Spa
Received on Tue Dec 14 04:37:32 2004