All this philosophising and questioning the existence of a soul, or whether there is a purpose to your life other than a strictly evolutionary one (survive, pass on your genes) is probably because humans have the capacity to think about such things.
If you equate life in all its forms with the process of evolution, there is no purpose other than the emergence of new species to replace extinct ones. Evolution does not however, predict what a species will look like, what it will eat or what niche it will occupy, only that a species will eat something and will occupy some niche, i.e. that given an opportunity some species will emerge which exploits it.
The purpose of your individual life therefore, in evolutionary terms is to exploit some opportunity and have some advantage because of that, to pass on your genes and ensure the persistence of your species, and of course to die at some point so your species' progeny can continue to exploit the same opportunity.
Otherwise, you can perhaps realise why you're here, what you are in the scheme of things, and what your life really is, maybe. Or just follow the crowd, if the former option seems like too much effort. And yes, I'm talking about realisation of the self--enlightenment in other words.
