This is going to get a little science heavy before funny, so sorry about that:
There is a current theory that is floating around all the science papers that is trying to imply that life might not have started on earth, and that it is entirely possible that it arrived on an asteroid that was knocked off of another planet billions of years ago, because—as it turns out— that life (the microscopic kind) has no problem going dormant as it hurtles through space. A recent paper that was published by Ronald Breslow suggests that if the asteroid that killed the dinosaurs had headed to a habitable planet, say the recently discovered one 20 light years away, there could be a super advanced race of dinosaurs just waiting to take over earth hanging out over there.
The problem, as I see it, with this theory is several fold: The first is that it is now modern dino-theory that most of those creatures simply evolved into birds. It has been known (although until recently improvable) that most of the more advanced dinosaurs had feathers, so asteroid or not they would have become something else given all that time, and not simply remained giant thunder lizards—much of the same way that humans are not apes any more. The second is that it has taken all of those millions of years for life to evolve from a mild offset of a sudden impact, and the mammals at that time were pretty much glorified rats. A couple million years from bacteria or RNA would be lucky to produce plant life, not FTL drive Raptors.
Source: The Register