text: In the end , the narrator says that humans would never have existed if a chance collision in space 165 million years ago had n't occurred , sending an asteroid hurtling towards Earth and dooming the dinosaurs to extinction .
simplified: In the end , the narrator says that humans would never have existed if a chance collision in space 150 million years ago had n't occurred , sending an asteroid hurtling towards Earth and dooming the dinosaurs to extinction .