[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: Hybrids

Roger Miller writes:

<snip>> Isn't a hybrid between two species *supposed* to be sterile?  I 
>  that is the classical definition of species, so the "loss" of a species
>  through cross-breeding has always meant to me that the taxonomists'
>  definition of the species was incorrect to start with. 

Sterile drossbreeding is an "indicator" of species separation.  It is not the 
only standard, nor is it a necessity.  A prime example is the genus 
xiphophorus.  Swordtails, platies, and variatus are significantly different 
in the wild, and will not crossbreed given the option.  This makes them 
separate species, because the taxonomic differences are great enough.  But 
the plethora of colors seen in LFS tanks are the result of cross-breeding 
experiments and selective re-crossing.  If you want a pure swordtail today, 
you almost have to go down to Central America and get your own.  The same is 
true with mollies.

Bob Dixon
Cichlid Trader List Administrator        o
http://cichlidtrader.listbot.com               0