The emergence and evolution of birds has led, in time, to decrease the size of insects, thus allowing a safe evolution of mammals, implicitly, and man.
During their history, insects have now aproxiamtiv highest point of evolution 300 million years, the atmosphere was richer in oxygen than the present, and some flying insects reached a scale of 60 inches. Golden Age of insects was achieved during late Carboniferous and early Permian. In those ancient times, giant insects, like dragonflies present, but much larger sky ruled the Earth.
Then, during the emergence of dinosaurs, insects have got a series of dangerous predators and competitors: birds. “Even the late Jurassic and early Cretaceous, ie about 150 million years ago, oxygen levels increased, but insects suddenly began to lower dimensions. And this phenomenon, seemingly strange appearance coincides perfectly with birds.”
Said lead investigator Dr. Matthew Clapham, University of California at Santa Cruz. With the advent of insectivorous birds voracelor, insects have had to downsize to become harder to catch and easy to find places to hide from new enemies. The theory is supported by evidence related to biology pterosaurilor.
After the occurrence of these flying reptiles during the Triassic, insects have been a step decrease in body, but not as fast as the birds occur during the development stage. However, experts take into account other factors such as mass extinction at the end of the Cretaceous, leading to extinction dinosaur extinction.
“Personally, I think reducing the ability of insects and birds delivered to specialize. First birds were flying some very skilled. But the late Cretaceous, when birds already very much resembled today’s birds,” added Dr. Clapham.
Source: Daily Mai