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Magdalena Koziol, a former postdoc at Yale University, was the victim of scientific sabotage. Now, she is suing the...
Antiretroviral drugs can protect people from becoming infected by HIV. But so-called pre-exposure prophylaxis, or PrEP...
Two studies show that eating a diet low in protein and high in carbohydrates is linked to a longer, healthier life, and...
Considered an icon of conservation science, researchers at World Wildlife Fund (WWF) headquarters in Washington, D.C.,...
The new atlas, which shows the distribution of important trace metals and other substances, is the first product of...
Early in April, the first of a fleet of environmental monitoring satellites will lift off from Europe's spaceport in...
Since 2000, U.S. government health research agencies have spent almost $1 billion on an effort to churn out thousands...
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ScienceShot: The Rise of Jaws
6 July 2011 1:00 pm
A new analysis of the first fish with the ability to bite is giving paleontologists plenty to chew on. Gnathostomes—vertebrates with jaws, including shark predecessors, the forebears of bony fish (including our own ancestors), and now-extinct lineages such as the armor-plated placoderms—originated between 444 million and 416 million years ago. As reported today in Nature, however, their rise to dominance was more complicated than previously thought. Paleontologists had hypothesized that the evolution of different jaw types, from slicers to crushers, allowed the gnathostomes to rapidly replace jawless fish. But, according to the new study, jawless fish coexisted with gnathostomes for millions of years. It was only after 400 million years ago, when all the major jaw types had been established, that gnathostomes began to take over. Biting may have given the gnathostomes an evolutionary edge, but, like their blood-sucking relative the lamprey, jawless fish hung on for a long time.
See more ScienceShots.