As i see it and think KarlIsNotMyName expresses it.
The morality in human's societies was 'builded' as a tool by our specie on a long period, it is a survival trait. In fact, morality does not equate the specie's survival, mainly because the specie and its survival aptitude takes precedence over the human society morality.
From the point of view of our specie, the only behaviors considered as 'moral' are the ones that tend to improve its own survival chances on a long term. The morality in human's societies is mainly her derived work.
Therefore, the morality of individuals is not independent of survival considerations, wathever the individuals sanity or their views. Our mind is mainly the result of our specie's survival ambitions on thousands years, we cannot cut that link without loosing our proper identity as individual, our will is only the expression of our specie's will to survive at any cost, no more, no less.