I love how science puts things in perspective:
The earth is a microbial planet, on which macroorganisms are recent additions—highly interesting and extremely complex in ways that most microbes aren’t, but in the final analysis relatively unimportant in a global context.
Microbial life on this planet would remain largely unchanged were all plant and animal life eliminated, but the elimination of microbial life itself would lead in very short order to a completely sterile planet.
— Carl Woese
(1998) PNAS 95:11043-11046
(first paragraph from private correspondence with Mark Wheelis)
And that’s merely biology. Think physics…