Re: Species [arbitrary to a degree]

["David Marjanovic" <david.marjanovic@gmx.at>]

> As Jaime said; this "rule" is extremely arbitrary.  A change in a single
> gene can result in profound biochemical and pathogenic (disease-causing)
> changes between bacterial species.

Sure. I was just reporting. Actually this should have been an answer to what
HP Waylon Rowley wrote in
http://www.cmnh.org/fun/dinosaur-archive/2001Oct/msg00594.html:

> I think
> that's the best we can do until future geneticists can
> pinpoint the exact percentage of genomic change that
> quantifies the definition. Agreed?

-- such an exact percentage has been invented for bacteria.

> Even if it was widely used,
> [...]_Shigella_ is maintained as
> a separate genus because it's a damn nasty critter, to help avoid
confusion
> with "true" _E. coli_.

So I misunderstood the professor who seemed to state that as a simple fact?