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From: eklhad@ihnet.UUCP (K. A. Dahlke)
Newsgroups: net.origins
Subject: Isolation and Unique Species
Message-ID: <217@ihnet.UUCP>
Date: Mon, 15-Apr-85 11:49:49 EST
Article-I.D.: ihnet.217
Posted: Mon Apr 15 11:49:49 1985
Date-Received: Tue, 16-Apr-85 05:51:37 EST
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< I am an island >

	So often I have read words to the effect:
"All you have is some fossils, and carbon radiometric dating ... ".
Surprisingly, these comments typically receive very few rebuttals.
In my last article, I mentioned the substantial independent
biochemical evidence supporting evolution.
This evidence is ubiquitous, and simple reproducible experiments
repeatedly verify its existence.

	In this article, I shall briefly mention another major
branch of independent evidence, geography.
Although we cannot observe large-scale evolution in the laboratory,
our planet has provided many "experiments" for us,
in the form of isolated geographic regions (islands and lakes).
These isolated regions always contain unique species, related to
mainland life, but slightly modified.
I wish I could eloquently expound on this topic,
but I could never produce a better presentation than this week's
"Life On Earth" TV episode (PBS network).
If you missed it, watch for any rerunning thereof.

	How could new species appear in isolated regions if they didn't evolve?

	"Wait a minute!!" cries the creationist in desperation.
After all, evolutionary evidence rears its ugly head yet again, we must
bat it down, no matter how absurd the counterargument.
"There is a simple explanation.  Gawd created unique
species everywhere, and those on the mainland mingled and mixed.
When we got to the islands, we found some previously inaccessible species.
A simple uniform distribution of created species answers everything."
Long sigh of relief.

	I give a long sigh myself, but for other reasons.
The islands were not there when animals first appeared.
(I am not dealing with the "young earth" or "God is fooling our eyes" camps.)
Furthermore, the diversity of unique island species is highly correlated
with the island's time of isolation, and the number of niches on it.
Why should Hawaii have 4/5 of the world's drosophila species?
It doesn't contain 4/5 of the world's land area.
Rather, it provided many different environments,
and isolation (not many fly eaters).  These short-generation animals quickly
evolved into a dizzying number of species.
Why were 90% of Hawaii's indigenous plants unique?
Why are island animals (e.g. turtles) larger than their mainland counterparts?
Why do birds become large and flightless on islands.
Is flying expensive, and hard to justify without cats around,
or did God just snap his/her fingers again.
Why does evolution explain most of these phenomena.
Why can creationism explain none of this,
without resorting to coincidence, or continual divine intervention (unlikely).

	The "Life on Earth" series has given me valuable
insight into the evolutionary process.
More important, I am again reminded
of the complexity and diversity of life on our planet.
The beauty of a bird in flight necessarily
captivates evolutionists and creationists alike.
-- 

Karl Dahlke    ihnp4!ihnet!eklhad