Message 2005-05-0016: Re: PhyloCode

Sun, 13 Mar 2005 20:44:13 +0100

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Date: Sun, 13 Mar 2005 20:44:13 +0100
From: [unknown]
To: PML <phylocode@ouvaxa.cats.ohiou.edu>
Subject: Re: PhyloCode

----- Original Message -----
=46rom: "Yisrael Asper" <yisraelasper@comcast.net>
Sent: Sunday, March 13, 2005 6:01 AM

> Officially defining a dinosaur as a class
> of animals that includes what would be known to a layman as a bird =
is a
> redefining of the word dinosaur and so should entail rejecting the =
word
> dinosaur as unscientific and making a new word inclusive of both li=
ving
> and nonliving therapods.

In principle, I agree -- but in this particular case it's 30 years to=
o late.=20
The first proposal to create a Class Dinosauria which included Aves w=
as=20
published (in Nature!) in 1975. Especially since 1986 (when an influe=
ntial,=20
more or less popular, famous book was published) paleontologists have=
 been=20
preaching ceaselessly that birds are dinosaurs. This has now reached =
most=20
professionals, and remarkably large parts of the public as well.

By the way: have a look at=20
http://www.amnh.org/exhibitions/dinosaurs/bts.php?image=3D14#cap. No,=
 this is=20
not a bird under most definitions of that term. :-)

_Now, Reptilia is a different case._ Reptilia was defined as (I'm=
=20
paraphrasing here, I think) "the most recent common ancestor of turtl=
es,=20
lepidosaurs and crocodiles, and all its descendants" (thus including =
birds)=20
in 1986 -- in a dissertation. Sure, it was published soon afterwards,=
 but=20
this was at the _beginning_ of the time when the _cladistics_ revolut=
ion=20
reached vertebrate phylogenetics! This was a time when people who are=
 today=20
members of the ISPN published _classifications_ full of newly invente=
d ranks=20
like "megafamily", "grandfamily", "mirorder", "parvorder" and the lik=
e. It=20
took a lot longer till cladistics became widespread across fields as =
narrow=20
as vertebrate paleontology, and longer still till the idea of phyloge=
netic=20
nomenclature got more or less commonplace. Keep in mind that it still=
 hasn't=20
reached entomology, for example.

The idea that birds should be considered dinosaurs is quite a bit old=
er than=20
phylogenetic nomenclature. The book from 1986 mentioned above doesn't=
 even=20
mention PN. At that time, putting birds into Dinosauria was considere=
d=20
identical to _removing Dinosauria from Reptilia_ and to elevating Din=
osauria=20
to class or subclass status (in the latter case as a subclass of=20
Archosauria -- the name Reptilia was completely dropped by those auth=
ors).

It is therefore no wonder that just last Thursday I had a course at t=
he=20
university in which the terms "monophyletic", "paraphyletic" and=20
"polyphyletic" were explained -- and Reptilia was used as _the exampl=
e_ of a=20
paraphyletic group.=20

  

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