One suggestion as to how we all arrived here, is that we started with the introduction of alien bacteria from very early visiting aliens. Now someone is suggesting that we "give back" the same thing, to elsewhere in the Universe.
An article in the "New Scientist" volume 209 number 2798, dated 5 February 2011, by Stephen Battersby and titled "Go forth & multiply" (pages 41-43) sets out the views of Michael Mautner. Mautner's views ( read more click here) originally appeared in an article in the "Journal of Cosmology" volume five, page 982.
Mautner proposes that we should launch large numbers of very small spacecraft, packed with bacteria, and send them off to planets around other stars.
An editorial in the 5 February 2011 New Scientist, talking of Mautner's idea says "A twinkling flotilla of spacecraft cast into the darkness might be the ultimate expression of the selfish gene." It continues "...it should be pointed out that we are not necessarily the first creatures to have thought of this. Our Betelgeusian forefathers may have had the same idea 4 billion years ago, and set their seeds to fall on the fresh earth."
Maybe the occupants of UFOs are our gardeners, tending the results of that seed?