J.E. Shields jshields104@insightbb.com
Tue, 22 Jan 2008 18:49:39 PST
I'm going to post this to several lists. I apologize for the duplication to 
those who, like me, belong to more than one of them.

In the early 1980s, I read a fascinating little book by Vern Grant, called 
"Plant Speciation." It laid out, in what I thought was a fairly straight 
forward way, where new plant species might come from. Among the cases in 
point were the rain lilies. Grant used them as examples of new species 
arising from polyploidy and from parthenogenic mechanisms.

Now there is another book on speciation, which I just received my copy of: 
"Speciation" by Coyne & Orr, published in 2004, so really quite current. 
You can find it in Bookfinder, Barnes & Noble on-line, and probably other 
places. The cost seems to be about $60 (US), new or used, for the soft 
cover edition. It's called a textbook, but there are no "exercises" at the 
ends of the chapters.

As I work my way through it, I'm going to bounce my impressions of the 
material off my fellow list members. Maybe that way I'll absorb more of 
it.  More importantly, I'll be very interested in the comments of others 
who have an interest in speciation.

The conclusions seem to be, at first glance, that Ernst Mayr's definition 
of the "Biological Species Concept" is holding up well, with some 
emendations as we learn more detail about the subject. The Biological 
Species Concept was that a species is a population or populations of 
interbreeding individuals. It is also concluded that recent evidence points 
to natural and sexual selection being the dominant forces in speciation, 
and that genetic drift plays only a minor role. The authors conclude that 
allopatry, while important in most cases, is not always necessary for 
speciation. It is even concluded that "species" is a real entity, as 
opposed to being just an arbitrary rationalization created solely by the 
human mind for purposes of organizing information. I've sometimes not been 
so sure about that myself.

I'll be interested to see how the book deals with the dynamic aspects of 
species and populations. That is the part that fascinates me -- can we ever 
step twice into the same river of species?

If you are interested in the current state of the process of speciation, I 
think this is going to be the book that you must read.

"Speciation" by Jerry A. Coyne and H. Allen Orr, pub. by Sinauer 
Associates, Sunderland. Mass., 2004. IBSN 0-87893-089-2.

Jim Shields
in central Indiana (USA)

Jim Shields             USDA Zone 5             Shields Gardens, Ltd.
P.O. Box 92             WWW:  http://www.shieldsgardens.com/
Westfield, Indiana 46074, USA
Tel. ++1-317-867-3344   or    toll-free 1-866-449-3344 in USA

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