Great Transitions Interactive

This is a part of Great Transitions: The Origin of Tetrapods


The fossils of transitional creatures were key evidence for Darwin’s evolutionary theory, but none had been found when he published On the Origin of Species. Now, there are many examples of such fossils, which clearly show that big evolutionary leaps consist of many smaller steps.

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A first-hand account of the painstaking search for Tiktaalik, a creature with a mix of features common to fish and four-legged animals. Order Now »