Subject: Re: Can Cats and Rabbits Mate?
Date: 2 Feb 1994 20:57:43 GMT

In article <joelyonsCKIszL.AHu@netcom.com>, joelyons@netcom.com (Joseph
Lyons) writes:

|> My girlfriend and I got into a argument about this topic a month ago, 
|> and I really don't want to get into another argument but here it goes.
|> She told me that when she was a little kid a friend of the Family had a cat
|> who mated with a rabbit, and the cat gave birth to these animals that
|> looked  like both.  I immediately said Bulls**t.  She's an MD, so I thought
|> she knew better and explained it away by thinking that this tidbit went into
|> her brain before she developed an intellectual filter. (parts
|> deleted) I'm just interested in evidence one way or the other.

Well, Joe, you're interested in evidence, evidence you shall have.

Rabbits and cats cannot mate and produce viable offspring. Period. End
of story. I have no doubt that some really horny male rabbits might try
to mount a cat, but the only possible result is a brief moment of pleasure for
the rabbit.

Here's why:
1. .Cats and rabbits aren't just different species, they're from entirely
different orders of mammals. Cats are from the order Carnivora, rabbits
are from the order Lagomorpha (Nowak, 1991). 
.I stress that they are from different orders, because that's a good
indication of how closely related they are. Animals are classified by
different taxonomic levels that are roughly correlated to how closely
related they are. So, all members of a genera are individual species
that are closely related, but members of a family are closely related genera. 
.Once you get out to the level of orders, you're talking about animals
that are only distantly related. And cats and rabbits don't even belong
to closely-related orders. If you look at the mammalian phylogeny proposed by
Novacek (1992), you see that order Lagomorpha is most closely related to
order Rodentia, and both of those orders are most closely related to
order Macroscelidea (elephant shrews). Order Carnivora is most closely
related to an extinct order of mammals called the Creodonta.

BTW, you'll notice that rabbits are not "almost rodents." They belong to
a completely different order of mammals, and are most closely related to
pikas.

2. .Only members of the same species can mate with one another and
produce viable offspring. This is the basic definition of a species used
by biologists, known as the "biological species concept." In it, a
species is defined as "groups of interbreeding natural populations
that are reproductively isolated from other such groups" (Mayr, 1969).
Reproductive isolation can be caused by geographic obstacles, mating
behavior, or sheer weight of genetic distance.
 .Cats and rabbits weigh in heavily on the genetic distance side.
They're so distantly related that they cannot produce offspring, even if
they try. Your mention of the fox as a cat-dog hybrid has the same
problem -- even though cats and dogs are in the same order, they still
belong to different families. Foxes are a genera unto themselves, Genus
Vulpes (Nowak, 1991).

3. Both cats and rabbits, and cats and dogs, are also reproductively
isolated by light of their different mating habits. For example, female
cats are induced to ovulate by the barbs at the end of the tom's penis.
Rabbits have smooth penises - no barbs, no stimulation, no ovulation, no
eggs for the rabbit sperm to fertilize -- no babies, QED.

.And as to your assertion that the zoo is full of the results of
strange breeding combinations, nature doen't work that way -- trust me.
Mutants come from within individual species, and many of the weird and
wonderful strangeness you see at zoos are simply the result of
adaptation to a specialized habitat.

Diane Kelly
Duke Zoology

References cited:
Mayr, E. 1969. Principles of systematic zoology. McGraw-Hill, New York.

Novacek, M. J. 1992. Mammalian phylogeny: shaking the tree. Nature 356:121-125.

Nowak, R. M. 1991. Walker's Mammals of the World, Fifth Ed. Volumes I
and II. John's Hopkins University Press, Baltimore.


From: dkelly@bio5.acpub.duke.edu (Diane Kelly)
Newsgroups: alt.folklore.urban
Subject: Re: Can Cats and Rabbits Mate?
Message-ID: <2ip8ks$jn9@news.duke.edu>
Date: 2 Feb 94 22:14:52 GMT
Reply-To: dkelly@bio5.acpub.duke.edu (Diane Kelly)
Organization: Duke University; Durham, N.C., USA
Lines: 18


In article <1994Feb2.021232.798@earlham.edu>, kendrhe@earlham.edu
(Heather M. Kendrick) writes:
 
|> I learned that in my bio class in high school, but it has always
|> given me paws, er, pause.  Dogs and wolves are distinct species, are
|> they not? And yet, as far as I understand, their offspring are fertile.  Or
|> else our family got the wolf-hybrid fixed for nothing.

Dogs and wolves are a special case that no one has decided what to do
with yet. Genetically, they're pretty much identical -- and thay can
interbreed and produce fertile offspring. This sounds like they should
be the same species. But since dogs and wolves were classified as
separate species very early in the history of taxonomy, there's a lot of
inertia to be overcome before they're renamed...

Diane Kelly
Duke Zoology

From: dkelly@bio5.acpub.duke.edu (Diane Kelly)
Newsgroups: alt.folklore.urban
Subject: Re: Can Cats and Rabbits Mate?
Date: 2 Feb 1994 22:10:46 GMT
Organization: Duke University; Durham, N.C., USA
Lines: 27
Distribution: world


In article <CKKpxL.AJ4@rahul.net>, jayjames@rahul.net (Jay James) writes:
 
|> Actually, from what I understand from genetic engineering, it is possible
|> to cross practically any two strands of DNA together (called a
|> "transgenetic" combination).  Thus, they have introduced plant and animal
|> genes together (spliced bits of DNA plant code onto DNA animal code),

|> But seriously, I talked to a researcher who claims to have been part of a
|> project that crossed human genes with pieces of fish genes... ("Little
|> Mermaid"?!)  Of course, this was done in a Petry dish and it's not the
|> same as having a reproducing cell...

It's indeed possible to put genes from one species into the DNA of
another species using recombinant DNA technology, but this is a far cry
from making reproductive cells that will develop into a plant-human
cross.

Genes have been party to a lot of misunderstanding, making them objects
of unecessary paranoia (My God! It's got ... _GENES_ in it!). Here's the
scoop. A gene is a series of nucleotides within a DNA molecule that hold
the code for a single protein. That's it. So, if someone can get the
gene that codes for insulin out of human cells and into, say, a tobacco
plant, all you get is a tobacco plant that grows human insulin in its cells.

Diane Kelly 
Duke Zoology
