It is unprovable, because you can always posit a plan that matches the actual outcome from what was actually a random process. What the evidence does do is to weaken the claim that there is evidence for a plan.
The plan is clearly to do anything to live and reproduce...You can see the innate struggle against increasing entropy in most living things, even as death is certain, because certainty is death.
This isn't proof of a plan, life does anything to live and reproduce because life without those qualities would not be sustainable. Those traits could be accidental though. The plan also isn't consistent when you step back, everything from planets to the universe do not seem to be following this plan.
Nature produce plans - nature produced you and you have plans...And if you have plans it's not too much of a stretch to say other living things have plans too, and their degree of planning varies depending on their level consciousness, memory and intelligence. The detail of planning is a continuum between non-life, virus, microbes, plants, animals, and humans. The intention in planning, however, is mostly constant.
Or both nature and me produce no plans, our actions are the result of some set of variables that have led to this point. This isn't proof.
And you're still focusing on too narrow of a spectrum, you can't even be sure that life must follow these rules just that it has in the one example we have.
Too true - in this life it's good to be not too sure of anything because often we are wrong about everything. In the end it doesn't really matter to our everyday lives if you or I believe one way or the other...
Nature has a plan, it's called extinction. What is it over 90% of things which ever evolved have gone extinct. That's nature's plan to make things which are very, very, very likely to go extinct. Some may say that's it's a sieve, but if it's a sieve then why is the universe not filled with intelligent life, it's not a sieve, it's a death sentence. We're all made to die, eventually forever. Into the deep, dark night. All of us.