Path: utzoo!utgpu!water!watmath!clyde!att!alberta!ubc-cs!grads.cs.ubc.ca!majka
From: majka@grads.cs.ubc.ca (Marc Majka)
Newsgroups: sci.bio
Subject: Re: Evolution
Keywords: evolution
Message-ID: <3315@ubc-cs.UUCP>
Date: 28 Jun 88 17:12:09 GMT
References: <5944@bloom-beacon.MIT.EDU>
Sender: nobody@ubc-cs.UUCP
Reply-To: majka@grads.cs.ubc.ca (Marc Majka)
Distribution: sci.bio
Organization: UBC Department of Computer Science, Vancouver, B.C., Canada
Lines: 30

Jonathan L Orwant writes:
> I'm a bit confused about how special-purpose anatomical parts can evolve, 
> e.g. the evolution of a bird's wings from an unwinged predecessor.

There is an ENORMOUS body of literature on evolution, which you can
find in your local library (MIT has one, doesn't it? :-).  Read any
introductory book on evolution.  Stephen Jay Gould is a popular writer
who loves making evolution simple.  See his "The Panda's Thumb",
"Ever Since Darwin", and etc.

Special - purpose structures such as eyes and wings often have precursors.
A common example of a course that the evolution might take in making wings
is that of tree dwelling squirrels.  Squirrels with the ability to leap
more deftly from branch to branch would enjoy advantages in food gathering
and preditor evasion.  An advantagous adaptation like flaps of skin around
the legs which enable the squirrel to stay aloft (glide) longer would be
selected for.  Now, just add some time for the selecive pressure to do its
work, and voila! wings.

I don't think this discussion should be overworked on the net.  It is a
topic that is too well covered, and in simple terms, in easily available
references.  Enjoy reading and learning from them!

> -Jon Orwant (orwant@wheaties.ai.mit.edu)
> Pity me.  I'm a computer scientist. 

Pity me too - I'm trying to be one!

---
Marc Majka