. 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 , 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
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2007-03-20 13:44:05
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answer #1
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answered by Miss Karen Roe 4
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