One would expect a living fossil to show extreme stasis at the genetic level. Not so for the tuatara, a New Zealand reptile, reported EurekAlert1: researchers found that “although tuatara have remained largely physically unchanged over very long periods of evolution, they are evolving — at a DNA level — faster than any other animal yet examined.”

The tuatara is said to be the lone survivor of a class of beak-headed reptiles that co-existed with the dinosaurs 200 million years ago (see Live-Science for picture2). The rate of molecular evolution of this lizard-like animal, the researchers said, is much faster than that of cave bears, lions, oxen, and horses, which supposedly evolved from primitive mammals in far less time.

Based on this study, the authors are claiming that molecular evolution and morphological evolution have nothing to do with each other: “Many scientists have thought that molecular evolution would be fastest in animals whose physical form, or morphology, also evolved swiftly,” the article says. “The tuatara finding suggests otherwise, that there is no relationship between the two rates.”

But if evolution does not cause fitness changes at the genetic level that translate into body changes, from where did elephants and giraffes come?….

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