Simplifying the meaning of life down to replicating one's species DNA works fairly well on an 
animalistic level-- even a human level to some extent. However, our more evolved intelligence 
suggests that our survival mechanisms have become more obscure, and at first glance may seem 
contradictory.
All other species work in their own self-interest-- deer don't decide not to have children for 
the "greater good" of deerdom. If the deer population gets out of hand, deer starve or its 
predator population grows as well to keep it in check. Humans, in their quest to replicate their 
DNA as much as possible, have successfully upsurped any such natural checks-- our worlds' 
population has outgrown what the planet can sustain without artificial means. We have developed 
these artificial means to feed our population thusfar-- but at what cost?
The same intelligence that has allowed us to alter the food chain (food web?) so drastically has 
also given us the ability to see further down the paths we choose-- we can see that the Earth's 
population needs to decrease if we are to start a symbiotic relationship and not perpetuate the 
current, parasitic one. Because of this foresight, it could be argued that not having children 
for the good of the planet _is_ in fact working toward the best interests' of the human DNA. If 
we breed ourselves into extinction, how does that benefit anyone?
Executive summary: Save the planet- kill yourself!
Mike Kirby
Wholesale Slaughter Enterprises
http://clever.net/WholesaleSlaughter