And here's why.
Earth's history is divided into four major units of time, or periods. The Precambrian was first, followed by the Proterozoic, the Mesozoic, and finally, the Cenozoic. Scientists picked these periods based on 3 catastrophic events that shaped the history of the Earth.
The event that split the Mesozoic and the Cenozoic was the great asteroid collision that occurred around 65 million years ago. This event killed off many living organisms. This caused the great dinosaur extinction.
Sometime before 65 million years ago, some dinosaurs started evolving feathers and wings. Certain dinosaurs evolved into birds. It took one major catastrophic event to kill of dinosaurs but left birds here.
Now, here's the reason that birds are evil. Not only did they evolve from crazy as bat **** dinosaurs, but one major event, and birds might evolve back into crazy as bat **** dinosaurs! Then what will become of the human race?!? I'm disappointed none of the presidential candidates are discussing this important issue.