Farewell to species (but not yet!)

Mon Feb 7 13:15:06 CST 2000

R. de Jong wrote:

> I have always wondered why some people make such a fuss of
> distinguishing between paraphyly and polyphyly. If a paraphyletic
> group is defined as a group not including all descendants of a common
> ancestor, so is a polyphyletic group. If we agree that an orchid and
> an elephant have a common ancestor (be it far back in history) than
> the group orchid+elephant is a group that does not include all the
> descendants of their common ancestor.

Ah, but you are missing the *most important* difference between
the two terms -- that the paraphyletic group, though not including
all descendents, *does* include the common ancestor, whereas a
polyphyletic group does not.  This *is* an extremely important
distinction, which I do not feel that virtually anyone doubts on this


Dr. James K. Adams
Dept. of Natural Science and Math
Dalton State College
213 N. College Drive
Dalton, GA  30720
Phone: (706)272-4427; fax: (706)272-2533
U of Michigan's President James Angell's
  Secret of Success: "Grow antennae, not horns"

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