Please see
http://www.reasons.org/resources/apologetics/design_evidences/20020502_solar_system_design.html?main
If you hypothysize that advanced life can exist on a wide variety of planet types, not just an Earth-like planet, then I must ask you why no such life exists on any of the other planets or major moons. You see, we already have many "tests" of whether some non-earth-like animal life can arise. So far the "tests" (these other bodies on our solar system) have been negative. THis despite the fact that many of them have doubtless been seeded by organic material, maybe even organisms, from Earth. This is through huge impact events that sent chunks of Earth into space.
My assumption one based on fact.
If not, do you think they should be?