Fossils uncovered in 2004 and unveiled by scientists in April are being hailed as evolution's "missing link" between water- and land-dwelling animals. The fish species, whose remains were found in the Canadian Arctic, has been named Tiktaalik.

"It shows you that one of the great gaps, one of the basic steps in evolutionary past, is from water to land," said University of Chicago biologist Neil Shubin, co-leader of the discovery team. "It shows in exceptional detail what features evolved and changed at that time period."

The fish had a neck, big ribs, arm bones, and a functional wrist joint. Tiktaalik is the closest aquatic relative of land-living animals, Shubin said.

But Ken Ham, president of Answers in Genesis, which promotes young-earth creationism, called the claim "a big fishy story." He said, "There is nothing new about it, except it's a new genus and species."

He pointed to the coelacanth, a contemporary fish that also has bones in its fins. Those bones are not connected to its skeleton to bear weight, but instead help propel it along in shallow water or mud. Scientists once thought this fish, too, was an evolutionary missing link. But study of a living coelacanth showed it was simply well made for its environment.

"We already know some fish use their fins to prop themselves out of the water. Catfish do that, but they are clearly not evolving into land animals," said Casey Luskin of the Discovery Institute, which promotes Intelligent Design (ID). "The whole question of how fins turned into feet is not solved by this fossil." Even if it were a missing link, Luskin said, ID advocates would question whether such an evolution could have happened randomly through natural selection.

More about Tiktaalik is available ...