Re: Hierarchal vs Non-Hierarchal Interfaces to Biological Taxonomy

Bob Badour <bbadour_at_pei.sympatico.ca> wrote:

> > I'd start looking at the Tree of Life Project:
> > http://tolweb.org/tree/
 

> Which common bird is it that has three cohorts A, B and C where A and B
> can interbreed, B and C can interbreed but A and C cannot? Is it the robin?

I used to study genetics, and there are several types of animal that can do this - IIRC from my studies, there is a (super-)species of American prairie dog that has three sub-species - Rocky, Plain and Appallachian.

R and P can breed, and P and A can breed, but R and A cannot.

There is a point at which the genetic distance between two creatures leads not to hybrid vigour but rather to infertility and/or sterility of the resultant offspring (horse + donkey = mule).

Paul...

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