Isn’t it strange that we need to consume life in order to live…. Even the strictest vegans will need to eat things once alive to gain their energy. The simplest grains, beans and vegatables were all once alive. You can survive only for so long with eating rocks, mineral salts and solar power (like trees do).
I feel like this is more a hallmark of evolution than it is a scientific requirement. We could probably just synthesize/convert energy (think heat or motion, in the form of the sun / those volcanoes. waves) and survive. heck plants are masters at it.
I guess that is how we were built. We need to eat life in either higher forms or lower forms (but some form) to stay alive. You could say – we need to eat DNA.