Xref: utzoo sci.bio:1923 talk.origins:4592
Path: utzoo!censor!jeff
From: jeff@censor.UUCP (Jeff Hunter)
Newsgroups: sci.bio,talk.origins
Subject: The birds and the beaks
Keywords: evolution, birds, beaks
Message-ID: <404@censor.UUCP>
Date: 12 Mar 89 16:55:49 GMT
Organization: Bell Canada, Business Development, Toronto
Lines: 24


	Hello there. I was having a conversation with a friend recently, and
the question came up "Why do all birds have beaks?". I finally concluded
that somewhere just after archeopteryx there was an overwhelmingly successful
bird that ate nuts (or had some other compelling reason to lose teeth and
get a beak). Subsequent generations of birds got their beaks by inheritence,
and were able to modify them to different tasks rather than having to 
re-develop teeth. Alec instead concluded that beaks have some advantage for
feeding if you've lost your forepaws  ('cause they're wings).
	So what are the net.opinions. (Please note that I'm crossposting this
to sci.bio, and talk.origins. If your reply doesn't have much to do with biology 
please edit out sci.bio in your message. (And flame me by e-mail, if you wish,
for the previous sentence. Don't post to the net.))

	Another topic in the conversation was "What are beaks made of?" This
is in the sense that rhinoceros horn is made of compressed hair, or human
fingernails are modified hair. So are beaks modified bone, cartilage, hair,
feathers, horn, or does the question make sense at all?
	Thanks for the thoughts ...
-- 
      ___   __   __   {utzoo,lsuc}!censor!jeff  (416-595-2705)
      /    / /) /  )     -- my opinions --
    -/ _ -/-   /-     No one born with a mouth and a need is innocent. 
 (__/ (/_/   _/_                                   Greg Bear