Something similar I read, maybe it was scifi, or maybe that madman Terrence Mckenna, that postulated that humanity was evolved as a message delivery system for DNA through millenia. Code in DNA, imbue the bags of water and tissue and meat with huge self defense and self preservation drives, and voila! Your message is guaranteed delivery in 10,000,000,000 years.
Bacteria, viruses, DNA all outnumber us exponentially by huge factors. Maybe we're the byproduct, not the purpose?
Boy, that'll kick the ego right in the nuts, won't it?
Kinda takes the pressure off though.
Your body has 10x more bacterial cells than human ones - Boing Boing:
"Carolyn Bohach, a microbiologist at the University of Idaho claims that our bodies contain 10 times more bacterial cells than human ones (bacterial cells are a lot smaller and thus occupy less volume). Human genome researchers believe that at least 40 of our genes are bacterial in origin."