Chris Heiny
Ted and Mutations

Organization: Xerox Corporation, Webster NY
From: chris@eso.mc.xerox.com (Chris Heiny)
Message-ID: <1993May19.133915.1120@spectrum.xerox.com>
Reply-To: chris@eso.mc.xerox.com
Newsgroups: talk.origins


I just thought of an example counter to Ted's assertion that
all mutations (whether by his definition, or others) are
deleterious: feline polydactyly (that is, multi-toed cats).

While I don't have the reference with me (don't even recall
the name - I'd have to search the library at home), here's
the gist of it (as I remember):

- most cats have 18 toes (5/front paw, 4/rear paw)
- polydactyl mutants may have up to 30 toes (8 front/paw,
  7 rear/paw).
- poly may affect front paws, rear paws, or both ends, but
  both paws on an affected end will have the same number of
  toes
- extra toes are fully functional
- poly trait is dominant
- poly appeared within past 400 years (first noted near
  Boston, Mass in the 1600s), and has spread since (the
  exact location of where it arose is uncertain).
- 1/3 of cats in Boston area are poly at this time
- polydactyly is not harmful in itself, and is not coupled
  with any other harmful condition.  It may even be a
  beneficial mutation (better hunting/climbing), but has
  so far not out-competed standard toes.

Having recently read Gould's `Eight Little Piggies' essay,
I wonder whether feline polydactyly is the result of a new
mutation, or a mutation that reactivated an older gene (if
indeed, that older gene still exists).