informative units of organization

[John Grehan]

Norbert Hahn wrote

In my region all four taxa
>can be found sympatrically or in close proximity of one another. If one had
>was to ignore the subspecific classification an immense amount of
>phytogeographic information is lost.

Perhaps that's the rock bottom of the issue. If the units of labelling are
informative
about the structure of the world then they are worth having, whether one might
want to call the unit a species, subspecies or anything else.

John Grehan