From what dinosaurs became extinct? new theory
Some experts have long believed that the cause of the extinction of the dinosaurs 65 million years ago was the fall of a massive asteroid. However, a new analysis of a professor of psychology at the University of Albany suggests that dinosaurs were in trouble long before the fall of the asteroid. Professor and evolutionary psychologist Gordon Gallup and his former student Michael Frederick, who now works at the University of Baltimore, claiming that the occurrence of toxic plants, combined with the inability of dinosaurs to associate the taste of certain foods with the risk has led to the fact that their population has declined sharply at the time of the asteroid .
The acquired taste aversion - an evolutionary protection, which can be found in many species, in which the animal learns to associate the use of plants or other food with negative effects such as a feeling of sickness. To explain the protective mechanism, Gallup cites rats.
"The reason that the majority of attempts are not crowned with success, is to destroy the rats that they, like many other species, have evolved to cope with the toxicity of the plant," says Gallup. "When the rats met a new food, they usually try to only a small amount, and if they are bad, they show a remarkable ability to avoid this food again, because associate the taste and smell of it with an unpleasant reaction."
The first flowering plants, known as angiosperms appear in the fossil record long before the asteroid and right before dinosaurs began to fade. Gallup and Frederick argued that as the plant growth and development of toxic protect the dinosaurs continued to use them for food, despite the gastro-intestinal disorders. While there is uncertainty as to when the flowering plants became poisonous and how long it took for the dissemination of this feature, Gallup and Frederick noted that their appearance coincides with the gradual disappearance of the dinosaurs.
In addition to studying the spread of toxic plants during the life of dinosaurs, Gallup and Frederick investigated whether birds can (which are considered descendants of the dinosaurs) and crocodiles (also children) to acquire a taste aversion. It turned out that the birds instead of getting used to the taste, have developed an aversion to the visual characteristics of that from which they were bad. They know what they should not eat to survive. In a previous study, in which 10 crocodiles fed with different types of meat, some of which were slightly toxic, Gallup found that, like the dinosaurs, crocodiles have not learned to deal in their tastes.
"Although the asteroid was certainly important psychological deficit, due to which the dinosaurs were unable to refrain from the use of certain plants for food, had a major impact on them," says Gallup. "A common sight on the extinction of the dinosaurs, due to the fall of the asteroid, implies that the extinction of the dinosaurs must have been sudden, but there is obviously the opposite: the dinosaurs began to disappear long before the asteroid and continued to fade in the course of millions of years after it."