Appearance of Evolution
From SkepticWiki
[edit] Introduction
The fact that organisms look like evolved objects would look may be taken, if not as conclusive proof, then at least as a heavy hint that they did in fact evolve.
[edit] Discussion
Let us take dolphins as an example. Their mode of life involves pursuing fish in order to eat them. Hence it is clear that the theory of evolution predicts that in the course of their development, natural selection should have given them a streamlined shape allowing them to quickly and efficiently pursue fish. And this is just what we do see: so dolphins look like they evolved.
However, the appearance of evolution should not be taken on its own as proof of evolution: "looks like" and "is" are two different things. Take, for example, a submarine. This is also streamlined: it looks like it has evolved. But we know, of course, that it did not.
We know that it did not evolve because we know how submarines are produced: people design and make them. This is in sharp distinction from the dolphin, which is produced by other dolphins mating. So not only does the dolphin have the appearance of having evolved, but also we know that dolphins reproduce with variation and are subject to natural selection: the necessary conditions for evolution. Hence, the most economical explanation of why a dolphin looks like something that evolved is that it is, in fact, something that evolved.
Another distinction between the dolphin and the submarine is that the submarine's superficial appearance of evolution is just that --- superficial. When we look at the deeper anatomy of a dolphin, we find that its body plan is plainly an adaptation of the basic mammalian body-plan, which is just what we would expect on evolutionary principles. This is what one would predict on the theory that the dolphin is a product of evolution: it is not a prediction of unscientific alternative claims, such as that the dolphin was intelligently designed. By contrast, when we look at the submarine we do not find that its basic design is an adaptation of an automobile. In the same way, when we look at a bat, we find that its anatomy looks like an adaptation of the mammalian body plan: when we look at a designed object such as a plane, we do not find that its design is a variant on, for example, that of a combine harvester.
To summarize, not only do living things have the superficial appearance of being products of evolution, but also their fundamental anatomy has the appearance of adaptation; and we know that living organisms reproduce with variation and are subject to selection, which is the necessary and sufficient condition for evolution to take place. Even if we had no further evidence for evolution (and we have lots) the most plausible explanation for the appearance of evolution in organisms would be that they did in fact evolve.
