Re: Acceptance of macroevolution

Arthur V. Chadwick (
Fri, 12 Dec 1997 10:07:34 -0800

At 08:00 AM 12/12/97 -0700, Gary wrote:

>As someone on this listserve observed a few months ago (unfortunately I
>forget who, and don't have time to search the archives now), in the
>creation/evolution debate, "microevolution" often means "the kinds of
>changes we agree can happen over time," and "macroevolution" means "the
>kinds of changes which we don't agree can happen ever." Hence,
>microevolution is possible and observable, and macroevolution is impossible
>by definition. But settling arguments by stipulating definitions won't
>work, of course.

If we stuck with the standard definitions found in General Biology texts we
could communicate more effectively. These elementary definitions from
Purvis, Orians and Heller will work:

Microevolution: The small evolutionary changes typically occurring over
short time spans [i.e. potentially observable]; generally involving a small
number of traits and minor genetic changes [i.e. speciation].

Macrooevolution: Evolutionary changes occurring over long time spans [i.e.
nonobservable] and usually involving changes in many traits [among major
taxa - Starr and Taggert]

These should be acceptable to everyone. I am still waiting for the
evidence of speciation events that I do not doubt occurred (I believe a lot
of microevolution has occurred). Within the last week, two different
individuals on this listserve have stated that speciation has been
observed, and I asked them to give me instances. I believe speciation has
occurred, a lot of it, but I am still anxiously waiting for the
observational evidence.