The argument between Biologists, Intelligent Design people, and Creationists is a curious one, sociologically. I won't go into it now. But one feature I would like cleared up is whether there is direct evidence of the appearance of new species. By this I don't mean new types of animals that cannot breed with the old types for behavioral or physiological reasons--- the Chihuahua and the Great Dane, say-- but a new type whose DNA is different enough to be a new species. Creationists say there is no evidence, and a strongly anti-creationist article from Scientific American seems to grant their point, if you read between the lines and see what the article does *not* say. Is there a better account than this one?

12. Nobody has ever seen a new species evolve.

Speciation is probably fairly rare and in many cases might take centuries. Furthermore, recognizing a new species during a formative stage can be difficult, because biologists sometimes disagree about how best to define a species. The most widely used definition, Mayr's Biological Species Concept, recognizes a species as a distinct community of reproductively isolated populations--sets of organisms that normally do not or cannot breed outside their community. In practice, this standard can be difficult to apply to organisms isolated by distance or terrain or to plants (and, of course, fossils do not breed). Biologists therefore usually use organisms' physical and behavioral traits as clues to their species membership.

Nevertheless, the scientific literature does contain reports of apparent speciation events in plants, insects and worms. In most of these experiments, researchers subjected organisms to various types of selection--for anatomical differences, mating behaviors, habitat preferences and other traits--and found that they had created populations of organisms that did not breed with outsiders. For example, William R. Rice of the University of New Mexico and George W. Salt of the University of California at Davis demonstrated that if they sorted a group of fruit flies by their preference for certain environments and bred those flies separately over 35 generations, the resulting flies would refuse to breed with those from a very different environment.

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