Yes in a sense. All the water that exists on Earth came to Earth during the Great Bombardment. During this event ice laden comets struck the Earth for a period of some 100 to 500 million years. We know life first formed in the oceans, so in a roundabout way our ancestors did come from outer space. If you meant like an Ancient Astronauts kind of thing, then NO, we are not products of an intelligent alien species. We built the pyramids and the all the other wonders of the world all by our amazing little selves.