I'll take a look at your smoking example first... Lets not get crossed between our words here - bad and evil. Smoking is bad for your health, is it evil? Some (very few) would say that it is evil, possibly destroying the temple of your body, but then there is the other side that would say that rape is not evil. (ugh... may be a poor assumption, but Im going to say rapists don't consider it evil.) It is very true that this decision is primarily based on one's environment, I will give you that, however, for the majority of the human race, there is a general consensus on what is acceptable and not acceptable on the ethical level. (e.g. generally murder, rape, stealing, lying, etc are considered immoral, while mercy, grace, hospitality, and kindness are considered progressive to the morality of the world)
In other words, while some may be devious in their opinions, based on an extreme environment (e.g. strict religious standards, cult standards, psychological instability, parental instability), the majority of the world has a consensus view on morality.
Hoarding food, mates, and territory sounds like some instances of the human race. I hope this doesn't diverge too much into political debate... but while I see the United States "hoarding" food, I don't see this as a purposeful attempt to be superior or inflict harm on others. I do see the United States providing much needed aid throughout the world (although not to the extent that it could).... I think the hoarding of territory is based on higher motives than geographical superiority, I see a great deal of sharing and building of civilizations upon the same soil. I look at Israel and I no longer see a conflict over land, but a conflict over religious indifference, holocaust emotions, and animosity over the zionist movement..... Finally, mates, well, unless you're Mormon, I think I'm right.

And on to Dave's favorite topic... death... Post-death life need not be discussed, and although I believe in life-after-death, I still see death as a stage in life. However, on that desert island, I can perceive living and dead, life and death, and realize on those perceptions that.... 1. I am alive. and... 2. Death doesn't look too good, because you stop moving for as long as I can tell, and you start to smell bad, and small bugs land on you, and you start to decay... so conclusion 3. Life is preferred, and it is wrong for me to take a life... (ugh, which begs the question, is fair/unfair a learned concept)
I'm done thinking for now... be back later tonight