Umm, define "life"? If it is any living organism, then "people" is a subset of life. While "life" may be able to exist without "people", but "people" can't exist without life, it depends on where you fall (in "People" and in "Life, or just in "Life", or in neither) that would give you your perspective, and probably influence your answer. So, to me, since I belong to "Life" and to "People", I would say, both. However, if you are talking about an individual element of either of these collections - a single Person, in the case of "People", or a single "Organism", in the case of "Life" elements not belonging to "People", I would say Person was way more important than any other "Organism" - to the extent that any comparison is almost meaningless (I'd see alot of individual "Organisms" die before a "Person", unless I have cause to not think much of the "Person").