It seems to me that when you say that the purpose of life is to support other life, you are begging the question: life Is for the sake of life itself.  There are teleological interpretations of life (example: evolution is for the sake of preserving the species) and there is teleonomy (life forms evolve through chance).  Yet all of them are merely different ways of begging the same question.  Logicians call this a petitio principii. It is a circle through demonstration. It really explains nothing, in my judgment. It begins where it ends (with the presupposition of life).

The purpose of life is to facilitate the continuous process of evolution of the organism eventually leading to salvation or nirvan or moksha which is the goal of the human life. This may take many lives to achieve. Starting from cell which is the fundamental unit of life, which over several life times may grow into bacteria which following similar process may grow into insect then fish then bird, animal and eventually monkey and then into a savage man who over a several life time may get transformed into a saint who after a several life times may succeed in having a vision of God and then himself become an angel who may have to be reborn many times on earth and lead the humanity towards its goal and then if he is lucky enough may get his own salvation which is the union with God.

I have started from the cell because if I go lower than that, the scientists will raise their eyebrows. Some scientists believe viruses have life, some believe they don't. I believe they have life but do not have consciousness. Life and consciousness are not the same thing. Cell and above have both life and consciousness. As the life form evolves, it manifests more and more of this consciousness and eventually the

mind of a saint finds itself swimming in the ocean of consciousness without limit. Below the viruses are self replicating molecules, atoms and fundamental particles of physics all of them have life but no consciousness. Scientists do not know from where these particles emerge. In my judgement they emerge from the ocean of limitless consciousness. So the entire universe arises from this limitless consciousness and returns back to this limitless consciousness. What is the driving force? Driving force is the joy and bliss associated with the consciousness which is the goal of the human life. Joy and bliss of the illumined person is far superior to anything known to the carnal man. It is permanent and everlasting.

Thank you for that interesting philosophical analysis Dr.Nelson Orringer. To expand on what I was proposing: Once a life form (ability to replicate almost exactly the same) was evolved immortality became a reality and life exits in one form or the other as a replicating nucleic acid and each life form support the existence of another (except may be human beings?).