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From: chris@mimsy.UUCP (Chris Torek)
Newsgroups: sci.bio,talk.origins
Subject: Re: The birds and the beaks
Keywords: evolution, birds, beaks
Message-ID: <16816@mimsy.UUCP>
Date: 10 Apr 89 01:39:28 GMT
References: <28330@apple.Apple.COM> <3561@aplcomm.jhuapl.edu> <28434@apple.Apple.COM>
Organization: U of Maryland, Dept. of Computer Science, Coll. Pk., MD 20742
Lines: 38

>In article <3566@aplcomm.jhuapl.edu> jwm@aplvax.jhuapl.edu.UUCP (Jim Meritt)
>writes:
>>I don't think I am mincing words.

(Neither do I; but then, I do this sort of thing often :-) )

>In article <28379@apple.Apple.COM> sabol@Apple.COM (Bryan Sabol) writes:
>... Mutations are much more commonly deleterious than advantageous.

True (or rather, `we believe this to be the case').

>... It is true that "a trait that is not selected against continues",
>but neither does it change.  Without the advantageous mutations, the
>population/species would never change ....

Except possibly to cease to exist.

>[no] new species would develop at all....  So, if you really wanted to
>be specific about how you phrase the process, it would be more accurate
>to say that the filter that "does the selection" removes the deleterious
>mutations, but the manner (at least for this arguement) in which new
>species develop would be from advantageous mutations.

Yes;

>Therefore, one should say "why does ___ have ___", and not
>"why doesn't ___ have ___".

no.

Actually, the question should then be `how might group G have acquired
property P, and why might G-with-P be all that have survived to this
day'---in this case, how did proto-birds acquire beaks (what sort of
progression from teeth to beaks seems likely) and why did the beakless,
toothy proto-birds disappear?
-- 
In-Real-Life: Chris Torek, Univ of MD Comp Sci Dept (+1 301 454 7163)
Domain:	chris@mimsy.umd.edu	Path:	uunet!mimsy!chris