Science, from the perspective of evolution, can give us a remarkably simple explanation of  the notion of ‘death’. Simply put: it’s beneficial. Not to the individual organism, but rather to its genetic information. Death allows for adaptability as each new organism that comes to life has varied genetic information from the previous generation (in most species) and this in turn could provide better traits for surivival in the continuously changing environment. So in a way, genetic information is potentially immortal, though in return it gives up a piece of its “essence” every generation. That leaves us individuals in the crossfire of evolution: we have life and death at the benefit of genetic information but at the expense of each of us individually.