RE: Ancestors... (was Re: Stratigraphy, biogeography & cladograms )

["Stewart, Dwight" <Dwight.Stewart@VLSI.com>]

        -----Original Message-----
        From:   William Hinchman [SMTP:bsaurus@bellatlantic.net]
        Sent:   Wednesday, January 20, 1999 10:02 AM
        To:     Dino List Server
        Subject:        Re: Ancestors... (was Re: Stratigraphy, biogeography
& cladograms)

        Thomas R. Holtz, Jr. wrote:

         

        It had been my understanding that "species" was the reality and all
        groupings 
        above that level were man made.  Is it not so that to be the same
        species an organism 
        must be able to mate with a like organism and produce a viable
        offspring? 
        (obvious exceptions - single celled life and parthogenetic
reproduction)
        If species
        is also a human construct, what would be the definition?

        Bill Hinchman
        @@@@@@@@@@@@@@@@@@@@@@@@@@@

           Well, I think it's one caveat of species that the animals have to
be able to produce viable offspring, naturally.  But, I took viable as
meaning that
        the offspring are capable of reproducing.  A mule is the sterile
offspring of
        a horse & a donkey.  I was taught that mules are sterile BECAUSE a
horse &
        a donkey are not the same species.  I'm sure if that isn't the case,
there will be a zoologist on the list can give us the facts.

        Dwight