I don't believe in God, and as such my answer is either that there is no meaning, or that the meaning simply is to exist. Considering evolution, one could say that the purpose of every species is to keep their species going, and make it as suitable for it's role as possible. However, I believe that this is no longer the purpose of species that form larger societies, such as ants, termites, and humans. The purpose of these species is to make their societies as strong as possible. However, since there is no end goal, I don't see why anyone bother, apart from the fact that we are programmed to bother.