Re: What Are the Race Deniers Denying?

John Wilkins (
Tue, 08 Oct 1996 13:47:32 +1000

In article <53cbse$>, () wrote:

|The contrary is also the case! You'll be very interested to learn
|that biologists have discovered that it does not take isolation to
|create *species*! The September 13 issue of _Science_ has a
|"Special News Report" (the first one I've noticed in _Science_:
|maybe it's a new feature), called "On the Many Origins of
|Species." The summary says, "Researchers thought it took mighty
|barriers like mountains to make new species. Now they are learning
|that the process can rest on something as slight as a taste for
|new fruit." What this means is that one group of animals in a
|species starts specializing in eating one kind of fruit and
|another group in the same species starts specializing in eating a
|different kind of fruit. In time, these two groups co-evolve with
|the different kinds of fruit they eat and start heading in
|different evolutionary directions and eventually become new
|species. Now we know this happens on a larger scale, and the
|reason that plant became so colorful, in spite of the fact that
|green is the most effective color as far as photosynthesis goes,
|is because of coevolution with animals. (I'd have to look up when
|this happened.)

This is known as sympatric speciation and has been around as an idea at
least fifty years or more, at least since Mayr proposed the distinction in
the early 40s. It was denied for a time because allopatric or peripatric
speciation (of isolated populations) was thought to be the only way the
necessary variations could go to fixation and act as isolating mechanisms.
However, in the 70s, sympatric speciation made a bit of a comeback (there's
a ref to it in Gould's _The Panda's Thumb_ of 1980). Sympatrism is
relatively well accepted SFAIK, and rests exactly on divergence in
ecological niche exploitation.

John Wilkins, Head of Communication Services, Walter and Eliza
Hall Institute of Medical Research
It is the glory of science that it finds the patterns
in spite of the noise - Daniel Dennett