The evolution of the striking, wing-like pectoral fins of skates and rays relied on repurposed genes, according to new research by scientists from the University of Chicago. Studying embryonic skates, they discovered that the rear portion of the fin is built by typical limb-development genes; but the front portion develops through a different set of genes that are usually found in the shoulder areas of other species.(more…)
New technologies have brought new significance to a set of fossilized jaws that Stephen Gatesy and colleagues found in Greenland 20 years ago. Their new analysis shows that proto-mammals were diversifying earlier than previously thought.(more…)
Researchers have discovered well-preserved pelves and a partial pelvic fin from Tiktaalik roseae, a 375 million-year-old transitional species between fish and the first legged animals, which reveal that the evolution of hind legs actually began as enhanced hind fins. This challenges existing theory that large, mobile hind appendages were developed only after vertebrates transitioned to land.
The scientists describe the fossils in the Proceedings of the National Academy of Sciences, online on Jan. 13. The piece marks the inaugural article for Prof. Neil Shubin, Robert R. Bensley Distinguished Service Professor of Organismal Biology and Anatomy, as a member of the National Academy of Sciences. (more…)
