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