Accidental debate leads to evolutionary finding

By By Jonathan Ng and By Jonathan Ng

By Jonathan Ng

Evidence of how fish evolved to walk on land had been missing until four years ago, when Neil Shubin and his team on Ellesmere Island in Canada discovered an animal that bridges the gap between fish and four-legged animals.

Neil Shubin, a University of Chicago professor of organismal biology and anatomy, gave students, faculty and community members a lecture about the “missing link” between fish and tetrapods, or four-legged animals.

Shubin knew he had to explore new places to find the fossils needed to link the evolution of fish with characteristics such as conic heads and fins to animals with flat heads, wrists and shoulder blades.

“How do you go from this thing that lives in water, breathes in water, excretes in water, lives its whole life in water to this thing that walks, lives and makes its living out of water?” Shubin asked a crowd at the Aline Wilmot Skaggs Biology Building auditorium on Wednesday.

Trying to resolve a dispute, Shubin and his colleague opened up an undergraduate geology textbook. Rather than resolving the dispute, they stumbled upon regions where, after years of excavation, they eventually found the missing link, which they named Tiktaalik roseae. This discovery four years ago was a front-page news story for The New York Times and instigated some controversy with creationists.

“One of the great steps in evolution is the origin of the steps themselves — the shift from fish to land-living animals,” he said.

Shubin is an internationally renowned paleontologist and has made many other major contributions in his field, including contributions to the understanding of the earliest mammals and their non-mammal relatives from the Triassic and Jurassic periods about 200 million years ago, as well as having helped discover the earliest jumping frog. He is also the author of the book “Your Inner Fish.”

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