Ancient fossil found in Canadian Arctic shows evolution from fins to feet: scientists

Author: Margaret Munro

Source: http://news.nationalpost.com/2014/01/14/ancient-fossil-found-in-canadian-arctic-shows-evolution-from-fins-to-feet-scientists/

Published: Jan. 14, 2014

Summary:

A 375-million-year old fish,  known as Tiktaalik roseae. uncovered in the Canadian Arctic a decade ago continues to provide information to evolutionary biologists. Scientists reported Monday that the back end of this extinct fish has helped to reveal a large factor in the evolution of fins to feet. Tiktaalik had sturdy, mobile hind fins that it may have used to walk on as it slithered around shallow water and mudflats, say paleontologists. Scientists also say Tiktaalik’s large pelvic bones indicate the evolution of four legged locomotion occurred less recently then we initially suspected. “It looks like this shift actually began to happen in fish, not in limbed animals,” the team leader Neil Shubin said in a summary of the findings. Along with these recent finding scientist have made many ground breaking observations when studying this particular fossil. It is not til just recently they have been studying the hind section of the fossil, but prior to this particular observation scientists have made many key observations about the organisms front half. Both its head which seems to be a cross between a crocodile and fish, and its large pelvic bones this organism is an important example of the shift from fish to tetrapods.

Connection: This connects to chapters 14 and 15 in our textbook which are about evolution. We talked a lot about how the reason after a mass extinction the remaining organisms thrived due to increased opportunities. The reason the first fish moving to land was a beneficial trait was because similar to after a mass extinction the land was full of new opportunities, so the fish that could obtain more and more of these resources had a distinct advantage over other members of their species which through natural selection (another topic of the chapters) there was a gradual shift towards certain fish becoming tetrapods.