@seldoncrisis Panspermia cannot be ruled out but it would kick the question of the origin of life way down the road. I do bet that life is a feature of the Universe, not just the earth. Panspermia is sort of the 180 degree opposite of life originating on Earth, still a single genisi but somewhere else. i would argue for a multiple genesis, gas clouds birth stars, stars birth planets, planets birth life, life leaves the planet, etc. This would allow for the variation to allow Darwinian evolution to happen.