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> From: "Brian Lauret" <zthemanvirus@hotmail.com>
> Reply-To: zthemanvirus@hotmail.com
> Date: Thu, 31 Oct 2002 16:05:46 +0000
> To: dinosaur@usc.edu
>> Bill Hunt wrote:
> I don't know about dinosaurs and other extinct animals, but in contempory
> zoology a species is defined by whether or not they can reproduce.  In
> other words, if a female and a male can produce viable offspring, then they
> belong to the same species.  If they can only produce sterile offspring; as
>in horse and donkey produce a mule, then they belong to the same genus, but
> not the same species.  All other classification beyond that is pretty much
> arbitrary or artificial.  Kinda hard to put these definitions to the test
> in Dinosaurs.  -  Bill
>> This definition is null and void when it comes to Snakes, and possibly
>> many other Reptiles and Amphibians.

    Well I would have to say that these folks are bending the definition of
"Species" or ignoring it altogether.  They ought to take a closer look at
the parents of the "Fertile Hybrids".    If the parents are from two
different genera and if they are indeed producing fertile offspring, then
perhaps those two different genera are in fact the same species, by
definition.  The differences in superficial appearence which caused them to
be placed in different genera in the first place may be differences in
subspecies or differences in races.   Look at the superficial differences
within our own species: hair, skin, eyes, stature, body type.

Richard Forrest wrote me this off line:

>>What about dogs, wolves and coyotees? Different species, but capable of
>>producing fertile hybrids.

  Domestic Dogs are derived from wolves.  Genetically dogs are closer to
wolves than any other Canid, closer to wolves than coyotes, closer to wolves
than foxes.   I know of no example of Dog/Coyote producing fertile
offspring.  (that doesn't mean there aren't any)   But there are many
examples of Dog/Wolf fertile "hybrids".  For this reason some scientists are
saying that Canis domesticus does not exist, that all dogs  are still to be
considered Canis lupus.  (don't ask me to cite a paper, I saw this most
recently on the Discovery Channel).  Dogs in various sizes, colors, coats
and shapes have been geneticaly manipulated by breeders over the past 20,000
years or so, but they have not managed to create a new species.  Canis lupus
has just been stretched, pushed, prodded and teased into new forms, but
within the chest of your Shit-zu or my Basset or the other guy's all
American mutt, beats the heart of a Wolf.
>>And occasionally a mule does prove fertile.

Has there ever been a case of a fertile male mule mating with a fertile
female mule and producing a fertile mulette??  Sounds like a line out of a
Dr Suse Book..
>> For example, take a look at some of the Fertile Hybrids being produced
>> at this forum http://forum.kingsnake.com/hybrid/
>> If you scroll down the page far enough you will see photographic
>> evidence that proves fertile offspring from crossing different Genera!
>> Included are Pituophis x Elaphe crosses, Elaphe x Lampropeltis crosses,
>> Pituophis x Lampropeltis, and many other mind boggling examples of
>> second, third, and even fourth generation fertile crosses.

Ok, I took a look at this website.  I am not familiar with these particular
snakes, but this begs the question as it bends the definition.  I suspect
that the Herps breeders here are doing the same thing that dog breeders have
been doing for a few mellinium(s).    Manipulating a single species to
produce many different forms, patterns and colors.
>> Such hybrids are extremely rare in the wild, but certainly could and most
>> likely do exist.

Probably because they are different populations, isolated from each other
long enough to manifest superficial differences in appearences, but still
all the same species.
>> It is entirely possible Dinosaurs / early Reptiles could do the same.
> Birds can certainly do this. There are some remarkable examples of
> intergeneric hybrids.I can give some in parrots (not because they more often
> do this,but because I know more about parrots then about other
> parrots.)there are examples of Galah (Eolophus)x Leadbeaters Cockatoo
> (Cacatua),lories from all genera interbreed without difficulties and
> Trichoglossus lories apparently interbred with King Parrot
> (Alisterus),aussie parrots from a number of genera happily interbreed as
> well and there's an example of Prophyrrhura(formerly Ara) maracana x
> Pionites melanogaster,two very different looking birds indeed.

See comments above.  A Jaguar and a Black Panther are two different color
phases of the same species.    I live in Abert's Squirrel habitat here in
Northern Colorado.  Another population of Abert's Squirrel, aka Kiabab
Squirrel, isolated from my population lives on the North Rim of the Grand
Canyon.  These two populations have been isolated from each other since the
formation of the Grand Canyon, and how long has that been??  They look
different, but are still regarded as the same species, perhaps different
subspecies by now.  Within my population there are two color phases; dark
charcoal gray and light gray.
> Furthermore,we shouldnt forget about various genera within fowl,ducks and
> birds of paradise interbreeding intergenerically.
> The thing might be quite common among birds and possibly dinosaurs in total
> as well.

As I said, tough to test in Dinosaurs, where we're sometimes not even sure
about anatomical differences due to sexual dimorphism, much less their
ability to produce viable offspring.  In the case of dinosaurs it is
legitimate to assign genus and species on the basis of anatomy and
morphology, since that's all there is to look at.   Not the case with living
plants and animals.
> Brian
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