An old theory...

One of the things that has fascinated scientists and science fiction types for a long time is the idea of seeding.

The base idea is that life on Earth did not start on Earth. In the more fantastic versions, an elder civilization planted life here. The more feasible ones blame comets and other interstellar debris.

Now a man named Mauri Valtonen has proposed an alternative - that other planets may have been seeded with life from Earth. He's looking for stars that formed close to the sun in hope of proving his theory.

Here's the thing, though. If we find DNA-based life on a star that formed close to the sun and it really looks like it's the same life - how do we know which was first? We're talking a very long time ago in the very early stages of the development of life.

It could give a new meaning to 'chicken and egg'.