Some days ago I had a discussion with a friend about possible alien life forms.
He was stating that there anywhere could be lifeforms that do interplanetary or even interstellar travel by jumping of from the planetarys velocity.
I tried to counter argue, while I had ideas in mind like it couldn't be because:
How a species should develop this way? What benefit would a species with its origin on a planet gain that requires it to jump into space, without which it wouldn't survive? And how should this mutate?
Gravity?! When thinking about the forces required for escaping earths velocity, assuming at what ever low scale the gravity of that planet may be, the energy consumption of such a being that it in theory could develop this jump trait would be so enormous, that it couldn't be provided with enough resources by such a planet, that there a whole set of species could evolve from a what ever state to a state where it is able to do this kind of jumps, before the planets resources in that way, useful for such a being would be completely harvested.
But actually I wasn't able to bring it to a point that would have been convincing, since both are sciences I'm not that much sued to.
So could one complete my assumptions with scientifically backed data, or if my arguments are wrong how can it be disproved?
Of course, in case I was wrong and this COULD actually happen, I would like to hear this as well.