"Didn't they teach you at school that birds evolved from reptiles?"
Some birds that stay active in winter have evolved elaborate mechanisms to generate or save heat.
Many paleontologists believe birds evolved from them some 150 or so million years ago.
Another of his ideas was that birds evolved from small carnivorous dinosaurs, a view widely held today.
Other birds probably evolved at this time, some modern, some now extinct.
But birds, with their great mobility, have evolved to cope with many of those problems.
The native birds have evolved to fill the niche that is otherwise filled by mammals.
That's why we birds never evolved very far, I suppose, despite our considerable intelligence.
Theropod dinosaurs are even more closely related, because birds evolved from them.
Most scientists believe that birds actually evolved from dinosaurs.