THE SCIENTIFIC AMERICAN article of snappy refutations for sci-guys to pull out when creationists bring up embarrassing questions that I linked to had this to say about the observation that no one has seen the evolution of a species. With a few comments:
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.
"During a formative stage" is doing a lot of work here. I wonder exactly how you define the "formative stage" of the evolution of a new species. Just what does it mean?
I wonder exactly what is meant by "speciation is probably fairly rare" in that, as I readily pointed out, every single known species alive today and those of the past almost certainly evolved from previous species. That's a hell of a lot of speciation. If it means that it doesn't reliably happen within the lifetime of anyone who's watching for it, I said that.
If "recognizing a new species during a formative stage can be difficult because biologists sometimes disagree about how best to define a species," then that certainly is a good excuse for anyone skeptical of such a claim to doubt it. That is unless it is clear, unambiguous and widely acknowledged as being that.
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.
I would certainly accept that an inability to interbreed with its close biological relatives is a pretty good part of what would define a new species, though in many cases animals recognized as of different species can interbreed and some of the hybrid animals of that mating can parent offspring. Lions and tigers, horses and donkeys, etc. So the definition isn't exactly definitive. I really have to wonder how wide the range of variation among the enormous numbers of different species that this definition is known to be true for. If the definition of what a species is is that inspecific, it only points to part of that enormous complexity of life which I mentioned but which evolutionary biologists like to figure they can figure out by making up stories about animals, plants, etc. in the lost past which they will never be able to study. The idea that Darwin figured it all out in 1859 with the information he had at his fingertips based on the political-economic theory of Malthus becomes more absurd than less absurd.
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, 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.
"Apparent" does a lot of work in that paragraph.
I wonder a number of things about that, not having read the literature on that experiment. One question I'd have to ask since what I'm interested in is NATURAL selection is whether or not their "new species" could survive as a distinct species in the wild, if all members of the "new species" refused to mate with all members of different populations (species?) and that's just the beginning. I would also wonder how universally their colleagues agree with the idea that they have created new species. I'd also wonder how long this "new species" persists as an isolated population if it doesn't breed with other fruit flies. How many individuals was it? Did that difference persist if the two populations were kept together for 35 generations?
Note that this is exactly what I pointed out about the claim that scientists could "create new species" as a means of supporting "NATURAL SELECTION" and as a refutation of intelligent design. I would admit that the design of such an experiment would involve the intelligence of the scientist doing it, though I'd wonder about the wisdom of trying to invent artificial species which, if they could breed in the wild, might be a catastrophe. I don't trust biology labs to keep their created creatures isolated because I know what screw-ups grad students, lab assistants and college profs are. As someone who is having a lot of trouble with an introduced Asian fruit fly in my fall fruit crops, we don't need a lab created one too.
But as an example of why science cannot be used to "disprove intelligent design" as a force in nature, it works pretty well. That so many professional scientists would seem to not be able to navigate the pretty straight forward impossibility of what they try to do is a pretty good indication that a lot of them aren't the most intelligent of thinkers when it's a matter of their pet ideologies.
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