Re: BBC E-mail: Scientists see new species born

From: bivalve <>
Date: Wed Jun 09 2004 - 18:40:04 EDT

> > Please define what a "species" is.

There are several definitions that are currently popular; generally there's a close match between the favorite organisms/techniques of a biologist and the species definition chosen.
In part this difficulty reflects the constant evolution of new species and the difficulty in drawing lines between them.

Just about anyone would agree that sexually reproducing populations that are totally incapable of reproducing with each other constitute separate species. However, the degree of difference needed in intermediate stages is debated, as the article noted. For example, there are several species pairs in the freshwater mussels that I'm currently working on for which my DNA data do not sort them out in agreement with the species names currently used. Some of these probably represent a single species, but others may be very closely related species or species complexes.

Almost as difficult to sort out are antievolutionary views are on speciation. In fact, most "professional" Intelligent Design advocates and many young-earthers accept evolution between species; however, at the grassroots level many antievolutionists assert that species cannot evolve into new species. As the creation of new species has been observed several times in both the lab and in nature, in addition to the numerous examples of transitions in progress and good fossil transitions, denying that new species can evolve is simply incorrect.

    Dr. David Campbell
    Old Seashells
    University of Alabama
    Biodiversity & Systematics
    Dept. Biological Sciences
    Box 870345
    Tuscaloosa, AL 35487-0345 USA

That is Uncle Joe, taken in the masonic regalia of a Grand Exalted Periwinkle of the Mystic Order of Whelks-P.G. Wodehouse, Romance at Droitgate Spa
Received on Wed Jun 9 18:54:27 2004

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