From: Chris Ho-Stuart <>
Newsgroups: nz.soc.religion,aus.religion.christian
Subject: Re: Evolution (was women in church)
Date: 7 May 1999 01:48:44 GMT

Able <> wrote:
> On Tue, 4 May 1999 14:08:10 +1200, "Paul Wilkins"
> <> wrote:
> >
> >The facts are that the appendix is responsible for digestive enzymes that
> >help herbivores process plant material. The appendix is a vestigal organ,
> >and us having come from an animal background is a very good explanation for
> >the existance of such organs.
>
> No it is not, it should have been bred out of us very quickly.
> It threatens the survival of the species.
> Appendix burst=death.

This is simply not true, in the sense that it is neither a prediction
nor a consequence of evolutionary theory that the appendix should
have been bred out of us very quickly.

The appendix certainly does not threaten the survival of the species.
And even if it did, this would be irrelevant. There is no process within
evolution that anticipates an extinction crisis and acts to prevent it.
Natural selection works on individuals, not on species.

The appendix is sometimes cited as evidence for evolution. I feel
this is overstated. Its absence (if we lacked an appendix) could
equally be cited as evidence, which makes the case rather weak. What
is more correct to say is that evolution serves to explain features
such as the appendix which would be otherwise a puzzle.

Another difficulty with definite statements one way or the other on
the appendix is that the body is sufficiently complex that we cannot
be totally positive about the role of the appendix. Many researchers
consider it to have a role in immune defence -- although others
feel its only real use now is financial support of the surgical
profession. It is hard to be sure, since the body is so complex
and has so many subtle interactions.

One thing we *do* know about evolution -- existing organs do get
co-opted to new purposes. It is possible that the appendix is a
digestive organ which has in part been co-opted to assist in our
immune defence system.

Outright removal of an organ in a single generation is not plausible.
Reduction of an organ takes time; and in this case might be
significantly slowed by a number of effects. It could be that
reduction in the size of the appendix carries a small loss in
fitness due to either loss of assistance to immune defense, or due
to an increased risk of rupture with the wrong kind of reductions.
This is entirely speculative -- and does not qualify as a good
explanation; we lack the data to know.

It does seem likely that the appendix is being removed, gradually, 
but this also is very hard to tell since we have no evidence at
all of sizes of these soft organs from fossil remains of extinct
species.

Cheers -- Chris