Anthropogenic "speciation"

[Fabio Moretzsohn]

Dear Jan and Taxacomers

I remember hearing about a discussion on a group of wallabies that escaped
from a circus early last century in Hawaii (Oahu). The wallabies then became
established, and today there is a small but breeding population that lives
in the brushes off Kalihi, Honolulu, not too far from the Bishop Museum.
Then a few years ago, someone did an allozyme study and proposed that there
were enough differences from the original population to recognize the
Hawaiian population as a distinct subspecies (imagine Hawaiian wallabies!).
However, later that study was apparently refuted by another author. I am
sorry that I do not have the references to offer, but maybe someone on the
list would know them. This case does not really fit your request, but at
least it is an interesting story.

I guess that this would be a classic example of founder effect: a small
population becomes isolated from the main population, and only a subsample
of alleles is represented in the new population. Provided they remain
isolated for a long time, there could be fixation of alleles and mutation,
and eventually they would become distinct enough to be recognized as a
subspecies or species.

The question is how much difference (genetic, morphological, behavioral,
etc.) is usually used as a yardstick to tell subspecies (and species) apart?

Aloha, Fabio

Fabio Moretzsohn
PhD candidate
Department of Zoology
University of Hawaii