Farewell to species (but not yet!)

[DR. JAMES ADAMS]

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
list.

        James

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"