From: Jay Willingham (jaywillingham@cfl.rr.com)
Date: Thu Aug 21 2003 - 14:06:06 EDT
A most excellent beginning for creating a course on the subject.
Whence cometh all things vegetable and mineral and temporal and powerful
(energetically speaking)?
Where did evolution begin? Eden?
Did it re-start on Ararat?
Man as the intelligent designer: selective breeding and genetic
manipulation.
----- Original Message -----
From: "bivalve" <bivalve@mail.davidson.alumlink.com>
To: <asa@calvin.edu>
Sent: Thursday, August 21, 2003 12:56 PM
Subject: Re: Student perceptions re evolution
Modern definitions of biological evolution generally focus on something
like a change in gene frequencies over time. Such a definition leaves aside
the question of how extensive a role it has had.
>
> We can observe the natural or experimental creation of new species and
genera. Given the somewhat arbitrary definition of taxa, especially higher
taxa, it is hard to claim that something is a new family, etc. However, no
particular barrier is evident to prevent larger changes, comparable to those
considered to distinguish major taxa. For example, the major groups of
arthropods (subphyla or classes) are distinguished based on the number,
position, and kind of body regions and appendages. E.g., insects have six
legs, in the middle, two antennae and jaws on the front, and no jointed
appendages on the back end. However, a mutant fruit fly has been made with
legs instead of antennae, thus disqualifying it from the basic characters of
being an insect. Likewise, the morphological and genetic differences
between higher taxa appear quantitatively rather than qualitatively
different from those at lower levels (in fact, a major difference in one
group may be a minor difference in!
> others).
>
> 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
>
> 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
>
>
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