About 500 million years ago, the first animals with a notochord — the foundation of a backbone — emerged on Earth. Today, the string of bone or cartilage that makes a vertebrate a vertebrate takes many shapes.
Katharine Criswell, a postdoctoral fellow at the University of Cambridge, look at how different species build this fundamental feature as a window into our deep evolutionary past.
Studies on the evolutionary origin of teeth and of vertebra further illuminate the human connection to marine organisms that goes back millions of years. Both studies in the little skate (Leucoraja erinacea) are published by Andrew Gillis and Katharine Criswell of the University of Cambridge, U.K., who conduct research as Whitman Center Scientists at the Marine Biological Laboratory (MBL), Woods Hole.
In the first paper in Proceedings of the National Academy of Sciences, Gillis and Criswell confirm the long-held assumption that teeth and the scales of sharks and skates have a common evolutionary origin. Moreover, their findings suggest that ancient fishes had multiple layers of external armor that evolved into the differing scale types we see today.
About the Author
*** She raised particular concern over what she described as the unauthorized insertion of language into draft ordinances by town…
What is a panek-a-tak ?
Once again, Another Vow of Tran$parency... How refre$hing.
Well written article. Let's see who is listening to the voters. Everyone's vote counts. What's behind the curtain should be…
Panek A. Tak is quite confident in her assertions about the alleged criminal activities of a former town employee. Perhaps…