Papilio joanae - ancestors?

Ron Gatrelle gatrelle at tils-ttr.org
Thu Feb 1 06:05:02 EST 2001


----- Original Message -----
From: "Stanley A. Gorodenski" <stanlep at extremezone.com>
To: <leps-l at lists.yale.edu>
Sent: Wednesday, January 31, 2001 6:31 PM
Subject: Re: Papilio joanae mtDNA - a reply


-- snip --

I was including responses from other individuals in my response.  I was
attempting to be less
personal so as not get anyones hair up, and so I did not want to say
"this argues against so and so's model that etc. As you pointed out,
there was no way you could have said this, and in fact I was using your
statement of what the mDNA analysis showed as evidence that P. joanae
was not likely to be the ancester of P. polyxenes. Unfortunately, I can
see now that because my response was directed to you it was easy to
interpret it the wrong way.  Sorry for the confusion on my part.  Next
time I won't hesitate to name names to avoid this kind of situation.

I will finish reading your response and will probably have more
questions.

Stan
___________________

FROM RON

No problem. In case someone missed it I am the one who put forth the idea
of joanae being the ancestor of N. American machaon group. Now, I did not
mean THE ancestor. I am looking at the possibility of joanae being the
extant species with the oldest connections. Why am I thinking along these
lines?

Is there a subconscious influence because machaon is the old world
swallowtail and was described first?  For example, if we see several
markers common to machaon and what ever - do we tend to say (think) that
what ever has machaon's characters rather than machaon has what ever's
characters? After all we do call this the machaon group. The problem with
this is that about 15000 years ago virtually all of machaon's current range
was covered with ICE - where was "machaon" at then? Was it even exisatent
then? If so how can that be proven?
Tree diagrams look good on paper. They may not look so good if laid out
over geological time.

Bear with me. Next. Basically - dark taxa inhabit the north - colorful taxa
the tropics. One of the reasons for this is that dark is a better basking
color to absorb heat in northern climates. Dark species have a thermal
survival edge in colder climates. Dark is also a selective species
preservation mechanism in times of glaciation.

Just because there is a genetic connection between joanae and machaon - it
does not automatically follow that it is in the direction of joanae to
machaon.  Connections are just connections. It is not just a matter of
which entities have the most amount of common markers (connections). It is
also a matter of which entity has the most connection to its fellow
entities. Does polyxenes have ANY genetic connection TO joanae? Does
brevicauda have any genetic connection TO joanae? Do the various machaon
sub taxa have any genetic connection TO joanae?  How about bairdii,
zelicaon, coloro etc.? If joanae has more genetic connections with its
fellows then they have with each other then I say joanae is the closest to
their common (dark) Pleistocene ancestor.  The fact that joanae has more
markers in common with machaon only shows that they are currently more
closely related than joanae is to some of the others (currently) -- all
these taxa are evolving, moving at different rates.


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