At 08:12 AM 4/13/02 -0500 Adam C. Lipscomb wrote: >No one alive today has observed Julius Caesar, either. Nonetheless, >we are able to confirm his existence through secondary sources. > >It's a bogus argument, and one that depends entirely upon mildly >clever word-twisting.
Now wait a second - I happen to believe in evolution just as much as the next geologist, but it doesn't bother you at all that we have *never* observed speciation? I mean, bacteria produce generations *very* rapidly. If no scientist has ever been able to produce speciation in bacteria, I think that that signals a *major* flaw in our understanding of evolution. JDG No, John, because speciation is not a bright line. Species are really rather blurry. How do you define a species? Well, I was taught in biology that a species is a group of individuals that can interbreed with one another but not with individuals outside the group. Right away you get into a problem with bacteria, of course, because bacteria _don't_ interbreed, they clone themselves. But are lions and tigers different species? We all know that they are. But they can _also_ interbreed. How about Irish wolfhounds and poodles? They're both members of canis domesticus (I think that's the latin phrase) but they sure aren't going to breed anytime soon. Are _they_ different species? So for bacteria the reason we've "never observed speciation" is that we've just never chosen to _call_ the changes that we've observed speciation. But we've seen staphyloccocus evolve from a version that is sensitive to penicillin to one that is resistant, for example. OK - call the resistant one a new species. That's perfectly legitimate. Now you've observed speciation in bacteria. Gautam
