Why would they think Earth was "seeded" with life? Why not start with
and prove or disprove life originated here? What is the attraction for
scientists of this theory?
The story you cite is about a meteorite that only contained organic
molecules, not organisms. It's pretty well accepted that all the
chemical components of Earth came from elsewhere - either from the
original birth cloud, or from later bombardment.
If organic molecules are widespread in extra-Earth matter, then
it's reasonable to ask if that is a significant source of organic
chemistry on Earth.
That's very different from asking if life originated here or came
here from elsewhere. It may also be reasonable to ask if life
fell to Earth from elsewhere. So far, there is physical evidence
for organic molecules falling to Earth, but nothing solid for life
falling to Earth.
Glenn Holliday [email protected]