Re: limits of variation

David J. Tyler (D.Tyler@mmu.ac.uk)
Wed, 26 Jul 1995 14:30:27 GMT

> It seems to me that everyone pushes the limits of variation quite far. Even
> YEC's like Gish and Morris believe that the dog-kind gave rise to foxes
> coyotes, wolves, hyaena's and the like. And if the YEC view of the flood is
> correct than all kulans, horses, zebras, asses etc must have arisen since the
> flood. That is a lot of variation especially when you consider that these
> equines have different chromosome numbers.It seems to me that evidence for
> rapid change is vital to the YEC view.
A very interesting book was published recently in Germany
(unfortunately mostly in german!) with the title *Typen des Lebens*,
edited by Professor Sigfried Scherer. It argues that Basic Types be
recognised in biological classification systems, and that
interbreeding be regarded as an objective criterion for inclusion
within a Basic Type. The details of interbreeding are thoroughly
discussed - hybridisation studies predominate here. Most of the
chapters in the book are case studies of individual Basic Types -
including both the dog family and the horse family. The
interbreeding criterion is used in an interesting way: if A and B
hybridise, and B and C hybridise, then even if there is no ercord of
A and C hybridising, they are considered members of the same Basic
Type. I mention these things because they can be used to support
the YEC views mentioned above (and for that matter PC views).

> [Further comments on dogs:] If you were to wipe out the mid-sized
> dogs, there would be almost no interbreeding between chihuahua and St.
> Bernard. The very thought is comical to say the least. And if PC or YEC's
> believe that foxes came from dog-kind, then speciation DID occur with them (as
> well as hyaenas.
As indicated above, a chihuahua will breed with XXX, and XXX will
breed with a St. Bernard.
YECs and PCs do (or should!) "believe" in speciation. Evidence for
speciation does not constitute proof for large-scale evolution, as
the same evidence fits happily within the YEC and PC thinking of
variation within a kind.

This is why picked up the issue of limits to variation: the
neoDarwinians must justify this assumption if their evolutionary
theory is to be considered science.

Best wishes.

*** From David J. Tyler, CDT Department, Hollings Faculty,
Manchester Metropolitan University, UK.
Telephone: 0161-247-2636 ***