OK, your point about the bears is reasonable, so I will cede the bear example to you; I don’t need it, because there are so many thousands of others. But it wasn’t quite cricket for you to present only pictures of Kodiak Island without snow! Cherry-picking the data, it’s usually called.
Because in classical Darwinian theory natural selection is the most important single cause of evolutionary change. It’s what serves as the designer-substitute, which brings about, as Richard Dawkins puts it, the appearance of design when there really isn’t any. (See the opening of The Blind Watchmaker.)
If “Darwinism” bothers you, then substitute “classical Darwinian theory.” But if you look through Gould’s Structure of Evolutionary Theory, you will see “Darwinism” and “Darwinian” used countless times, as if Gould thought the terms were not a problem.
“Probably”: indicating speculative, a priori reasoning.
Hard to quantify such things, and hard to show the organism doesn’t have the energy to spare.
I never said it didn’t. It might well have. My point was not that selectionist explanations are never correct or plausible. My point was that they cover too much ground, are too flexible – which was Dan Eastwood’s complaint against the idea of a designer (that it was too flexible, too facile at explaining any possible outcome, and hence hard to falsify or test in any rigorous way). And I’m not alone in this judgment. Both Stephen Jay Gould and Richard Lewontin, both of whom presumably knew a thing or two about evolution, offered the same critique of the selectionist “just so stories” often presented to explain why this or that feature is present or not present in a particular organism.