Sex and Species- A Question (was Re: sex)

Michael F. Hynes hynes at acs.ucalgary.ca
Fri Jan 5 14:01:20 EST 1996


The definition I suggested was for discrimination of species at
the finest level. There are indeed mnay barriers to production
of fertile offspring in animals, some of which are relevant,
and some of which aren't ( the fact that you might not be able to
mate a chihuaua with a great Dane doesn't mean they aren't members of
the same species).  What I think I was trying to say is that where
species are REALLY close, and can actually produce offspring (eg.
Mules from Horses and Donkeys, crosses between Lions and Tigers) these
offspring aren't fertile --- isn't this a DNA homology problem ?
When Species are not close, you don't have to worry as it is usually
fairly obvious that they are distinct. Incidentaly why are wolves
still classified as separate from dogs, when they can in fact interbreed 
?   I realise that plants are more complicated than animals as all sorts
of hybrids can be produced between alleged species, some of which are
fertile.

But any definition of species which is any good at all has to be 
universal, and I can't  see any way around a definition based on
DNA homology.

MH






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