Posted by:
CKing
at Sun Apr 26 02:30:29 2009 [ Report Abuse ] [ Email Message ] [ Show All Posts by CKing ]
>>>>>>>>>>Besides, who says a single instance of natural selection cannot be effective? Remember, natural selection acts upon existing variation. If there are x number of snakes at a locality and n of them have, by chance, the inherited behavior of favoring deep inaccessible crevices, then a single collector acting once (and acting illegally because of his disregard for bag limits) can possibly remove all of the individuals that do not have such behavior. >> >> >>Sorry but that is absurd. Maybe in a population of three, but I have never seen a population of three. Hence the need for repeated acts over generations to shift the behavior. KW would rip you up on this line of BS. >>
I don't know who KW is, but if he can refute my argument, then let it "rip." Apparently you invoked his acronym because you cannot refute my argument. I assume that you know how the dinosaurs (along with the enantiornithine birds) became extinct at the end of the Cretaceous. It did not take repeated strikes by a large number of meteors, just a single impact. That single event shifted evolutionary history irreversibly and drastically. It is simply old fashioned, outdated thinking to believe that evolutionary changes must be gradual. In many cases, gradualism works, but gradualism is not necessary nor is it the most likely explanation for all evolutionary changes. A single collector can indeed shift evolution in a single location, as surely as a single meteor impact can change the course of evolutionary history.
>>BTW collecting zonata is not illegal through much of their range. Further, the top of Mount Laguna has been repeatedly hit over decades and I do have that data. >>----- >>Rick Staub
I am sure that Mount Laguna has been visited by many collectors over the years, because it is accessible habitat. Perhaps this is one place in which human collectors have affected the behavior of L. zonata through natural selection. It was McGurty who sounded the alarm about L. zonata populations in that area dwindling because they were not being found in their usual hiding places at the time he wrote his paper. Perhaps extensive collecting has resulted in the removal of snakes that inhabited the more easily accessible crevices from the gene pool, and those snakes that remained simply had the natural, innate tendency to favor the deeper, less accessible crevices, and that such behavior is innate rather than learned. IOW, the Mt. Laguna population of L. zonata seemed to have been decimated, but in reality it is still pretty healthy because the habitat has largely remained intact and there were enough snakes that escaped collection (because they had the innate tendency to stay in deep, inaccessible crevices) to repopulate the area.
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