Some people think the dinosaurs died out because of a meteor striking the earth. Some people think they died out because of the coming of the Ice Age. And some people think they died out because evolving mammals competed more successfully for available resources. But new evidence proves beyond a shadow of a doubt that the dinosaurs became extinct because aliens poisoned their water supply.
The actual answer may be all, some, or none of the above. The writer should not assume that the new theory renders the others obsolete.