Re:Rahonavis....Both!

["John V Jackson" <jjackson@interalpha.co.uk>]

>>--Original Message-- From: Larry Febo <larryf@capital.net>To: T. Mike
>Keesey
>><tkeese1@gl.umbc.edu>: Thursday, February 25, 1999 01:22 AM
>
>>[snip]
>
>>[On the subject of the cladistic explantion:]
>
>>>Well, I think I`m beginning to understand
>
>>When you start to understand it, that's when you want to start worrying!
>
>I said I was starting to "understand" it, ...didn`t say I liked it ...(or
not).

That was supposed to be just my little joke!


>Computers may help sort out all the details, but human subjectiveness,
>in determining exactly what are proper symapomorphies to be plugged into
the
>equation,  I suspect may "prejudice" the truth in some of these cladograms.
>I`m suspicious, but will try (at least) to understand it.

Yes, there is subjective input into the cladistic process.  However all
refined processes grow out of subjective sentiments, and while the
procedures are being improved, the human thoughts make useful contributions.



>
>PS I may be "old fashioned", but I like to look for ancestors. After all,
in
>actuality, somewhere along the line....something BEGAT something else!

Yes.  Or near ancestors.  I think the idea that we shouldn't be looking for
ancestors has arisen through ancestors being not cladistics' stock in trade.
They *may* be rare in the fossil record, but that's no reason for us not
like to find them.



On 26 Feb 1999 09:52 in answer to Norton, Patrick
<Patrick.Norton@state.me.us>

[PN]<<Actually, if you accept Chatterjee's claims about Protoavis, you'd
have
to believe that flying avian forms were around much earlier than
that---since he claims that Protoavis is more a derived "bird" than
Archaeopteryx, even though it's considerably older.  >>

>Not if Archie is considered as having actually lost some of these advanced
>features (ie. acrocoracoid process and large sternum), and is on its way to
>becoming secondarily flightless at the stage in which it was found.

I think the wings would get smaller first, followed by the breastplate.
Losing the breastplate would save a little weight and might give a little
more flexibility, but losing the feathers would save a lot of tangling, and
shortening and solidifying the arms would save breakages.


JJ