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NFC: Gambrosia, not Damnbusia

On Gambusia:

Oh so maligned.  And why?
For exuberant fecundity (not a crime)? 

How shameful not to respect the weeds.

Like a ragweed (Ambrosia spp.) or dandelion (Taraxacum spp.), Gambusia multiply and cover the face of a continent, ever expanding into new environments.  And in each place colonized, potentially a seed... a seed for organic diversification of the highest order.

At first, an isolated few become adapted to their new milieu.  Then iimmigration (gene flow) from the common stock is a liability.  So adapted populations learn (evolutionarily) to shun potential mates from the ancestral pool.  The pioneers become ever more genetically (and phenotypically) different from the founders.  Lo, a new species.  A triumph... Endemism!  

So now we have new and different forms: Gila topminnow, San Marcos topminnow, Gambusia this, Gambusia that.  Hooray and gratitude for the weed.

So how to regard the wellsprings of diversification?  If not awe, perhaps a simple respect.   

Thom DeWitt

Dr. Thomas J. DeWitt
Department of Wildlife & Fisheries Sciences
Texas A&M University
2258 TAMU
College Station, TX 77843-2258

Tel. 979/458-1684; Fax 979/845-4096; E-mail tdewitt at tamu_edu