A photo from open sources
Birds, like turtles, smooth whales and anteaters, have no teeth. But it was not always so. Scientific discoveries suggest that in common the ancestor of all modern birds 116 million years ago was a kit snow-white teeth. In the process of studying, scientists observed mutated dental gene residues in birds to determine why did they develop “dentulism “- lack of teeth. From the ancients only fragments of their remains remained, but the study of their genes modern descendants will help determine how they happened development. “DNA from underground is a powerful tool in revealing Secrets of the History of Evolution, ”says Mark Springer, Professor biology at the university of california and one of the prosperous scientific researchers. “Modern birds have a curved beak and a strong digestive tract that helps them grind and digest food. But in 1861, in Germany, Archeopteryx was found Is an extinct bird species whose ancestor is presumably jagged reptiles, “says Springer. Scientists now know that the birds went from theropods – carnivorous dinosaurs such as tyrannosaurus rex – in the mouth which had many sharp teeth. The remains of the extinct Archeopteryx discovered in Germany were provided by the German Humboldt Museum in Berlin, where it can be fully consider. But no one can say for sure that happened to the teeth of these animals during evolution. “History tooth loss the ancestors of modern birds remains unsolved more 150 years, “says Springer. In a new study, scientists wondered the nature of bird loss of teeth – it was an isolated case, that is, one ancestor did not have all the birds teeth, or edentulism occurred independently in different birth lines in the process of history? To find the answer, genes were examined, responsible for the formation of teeth. In vertebrates in the process six enamel forming genes involved (hard tissue covering the teeth) and dentin (hardened tissue under them). Researchers tracked how these six genes mutated into 48 different species of birds, which allowed to see almost the entire process of their development. Mutations in the dentin and enamel gene bonds were common to all species of birds, which allowed us to establish that their common ancestor lost ability to form teeth. “The fact that more than 48 species a common deactivating mutation was observed in birds, suggesting that the outer layer of tooth enamel has been lost for about 116 million years ago, “says Springer. Researchers found mutations in enamel and dentin genes and in other vertebrates without teeth, including turtles, armadillos, sloths, aardvarks and lizards resembling the appearance of scaly anteaters. “Nearest a modern relative of birds among reptiles is an American an alligator, “says Springer,” but he has everything functioning. six genes for tooth formation. ”
Germany DNA Birds Evolution
