Dread and awesome Czar,
I thought “natural selection” and true “evolution” were two different things? Related, but different. Moths adapting their coloring, weeds naturally selecting to resist a herbicide, etc. are all “natural selection”. Isn’t evolution more like “fish growing legs”, Puter turning into GorT, and things like that? One species evolving into another one…
Yes and no, but what a superb question!
Natural selection is one process by which evolution can occur, but you are correct that they cannot technically be conflated. The Czar was pretty careful, he thinks, to use each term in its proper context, but let us review and the reader may judge.
Natural Selection is the result of a process of elimination. A rabbit with whitish streaks in his winter fur may survive a little bit longer in the snow than a brown rabbit. As a result, he lives long enough to reproduce, and some of his bunnies have the same whitish streaks during winter while others do not. The ones with whitish streaks survive longer, and are more likely to reproduce when they grow up. Those with even more white streaks can live maybe through two winters, and so they produce more bunnies. And so onuntil we reach a point where some bunnies are beconme totally white, and live longest of all through snowy winters. And because they live longest of all, they produce more all-white-in-winter bunnies, and eventually the others fade away over time.
That is pretty much all natural selection is. But it is a process that contributes enormously to evolution particularly when the advantages become in-born. You dont need to become a new species to benefit from natural selection, but most species today arrived there from natural selection.
Evolution is the process by which life changes over time. The changes do not need to result in or from new species, but only describe how they change over time.
We do need to be careful. Humans have changed over time: we are less hairy than we used to be, because clothing has made hirsuitism less critical for survival. That is an example of natural selection, not evolution: in a few generations, we can get back to hirsuitism pretty quickly. And we are taller than we used to be: but this is an example of improved nutrition and health, which is neither natural selection nor evolution.
Humans have evolved from an earlier form of primate, as did Neanderthals. But while we were biologically different from Neanderthals, we were (it is now assumed) biologically compatible: there appears to be Neanderthal DNA in something like 5-6% of the European-descended population. And that is evolution, not natural selection.
So when the Czar discusses weeds overpowering RoundUp he is describing both processes: the natural selection that allows some weeds to survive the herbicide surviving to pass on the resistence to others; but he is also describing evolution, as now all members of the species have become resistent to the stuff. This is one of those overlapping circles on the Venn diagram; but as GD points out to our readers, they really are two circles that overlap, not one and the same.
This brings up an interesting point about evolution that many anti-evolution folks do not understand: there is no perfect delineation between one species and another. This is the fossil gap fallacy. Opponents of evolutionary theory want to know why there is no clear fossil that shows (for example) a dinosaur turning into a bird. But this presupposes that dinosaurs turned into birds, rather than evolving into them. You will instead find hundreds of skulls, separated by hundreds of years, of very small, tiny, and seemingly insignificant changes. It is not until you step back, and pick two skulls separated by thousands of years (if not millions) and can clearly see the changes.
For example, scientists claim that whales evolved from a land creature like anthracotherium. Okay, the anti-evolution folks ask, where are fossils? So you find fossils of a creature called ambulocetus, which is a land-creature that lived in and near water that shows undeniable similarities to both anthracotheria and whales. Aha, they respond: so where are the transitional fossils between ambulocetus and whales? Dont have them, do ya? All right, respond the paleontologists: here are the bones for protocetus, which show a clear link between ambuloceti and whales. Aha, they respond in turn: but you cannot produce any fossils that link protocetus to ambulocetus! And so here come the paleontologists to show pakicetus, which does just that. Aha, comes the response…. You can guess the rest. So this game is euphemistically called the fossil gap: show us any two fossils, and we will point out there is a gap between them you cannot explain. Therefore, evolution is false. Which is like saying that the space between two cars stuck on the freeway is proof that traffic does not exist.
Well, the Czar is way off on a tangent here, so we will pause for a swig of Mr. Pibb.