I'll help out a bit. If you do a quick Google search on "evolution and the will to survive", you will get a pretty detailed explanation of how this will is absolutely necessary for any species to survive. Remember, over 99% of earth's species have gone extinct since life started, so not every organism/life form has this will to survive. We have many instincts programmed into our brains. We begin to breathe, our heart beats, our blood flows, our stomach digests. In the same way our will to survive is an inherent instinct. We panic and go into something called "survival mode" when faced with death, and there is an obvious reason for that. Those organisms that have this instinct have a better chance for survival and reproduction, which gives them the ability to pass this instinct onto the next generation.