By this I mean would it not make sense for the survival of all species that they be dependent upon themselves for reproduction.
How and why did nature decide that it would or could take the chance for two to reproduce? This seems to be quite risk for a organism to survive.
Indeed!
Who cares what the chances are for LIFE to arrive by chance, random selection or Space Aliens - it's what are the odds that cell critters decided to quit DYING and start SPLITTING!