Actually, you do: transitional forms like Archaeopteryx, a lizard-like bird, have been known for many decades, and more pop up all the time. But casts from a newly discovered fossil, slated to go on display at the London Science Museum tomorrow are, by all accounts, the most impressive example to date of a transitional form. They come from a remarkable creature, mostly fish-like but with some clear adaptations that let it operate on land. It fits perfectly with the conventional tale told by evolutionists the epochal moment when animals first began to emerge from their ancestral ocean.
The fossils of the approximately 9-ft. long creature, which are, described in two Nature articles released today, were dug out of rock formations on Ellesmere Island, in the Canadian Arctic, by paleontologists from the University of Chicago and several other institutions. Its nickame, for reasons that will become clear, is "fishapod"; it's more formally called Tiktaalik ("large fish in stream," in the local Inuit language). Fishapod dates from about 383 million years ago. It had the scales, teeth and gills of a fish, but also a big, curved rib cage that suggests the creature had lungs as well. The ribs interlock, moreover, unlike a fish's, implying they were able to bear fishapod's weightan unnecessary trait in a fish. It had a neckmost unfishlike. And, most surprising of all, its pectoral fins included bones that look like nothing less than a primitive wrist and fingers.
In short, fishapod adds one more brick, and an especially important one, to the edifice of Darwinian evolutionand at the same time puts the so-called theory of intelligent design into even greater question than it already faces. That would be true if only because any designer who deliberately made such a queer fish would have been more of a practical joker than anything else. But it also demonstrates that while evolution has plenty of missing bits of evidence, they keep showing up all the time to strengthen it. Evolution is, as ID supporters love to say, "just" a theory. It also happens to be one of the most successful scientific theories in history, whose predictions of what should be found in the fossil record have been proven outů for the zillionth time.