The BBC’s World Service Discovery programme [podcast] recently broadcast a piece on SETI and the Drake Equation. This included a segment [at 13 minutes into the podcast] from Professor Paul Davies [link link] about his theory that our genes may contain a message placed there by aliens who visited our planet millions of years ago.
Imagine an alien starship visiting Earth one to two million years ago. They want to leave a message for other explorers who may visit later. Perhaps millions of years later [slower than light travel has long time scales]. The problem is how to leave a message that stands a chance of enduring. Any building will soon disappear. Any message carved into a mountain would erode. A monolith would be swallowed by the earth.
Probably the only message which will stand a chance of enduring is one which multiplies, disperses and constantly renews itself. A living creature. So they created Homo Erectus, embedded a message in his genes and set him loose. Then they departed. Their creation might not survive, but it is the best they can do. Anyway, maybe the message is not very important.
Davies does not think this likely, but suggests that it would be cheap and easy to check with modern technology.
When I read this I remembered that I had seen this idea, of an alien message in our genes, many years before. In a science fiction story. A bit of research recovered the story. It appeared in the July 1965 edition of Analog Science Fiction. The stories title was Though a Sparrow Fall and the authors name was given as Scott Nichols. Nichols was a nom de plume of a well known author called Thomas N. Scortia. The three page story was nominated for a Nebula Award in 1966.
The story is remarkable imaginative given that it had only been twelve years since Crick and Watson had published their articles in Nature about the structure of DNA.
The punchline is excellent.