Morality is a built-in societal concept that comes naturally but is extended by thought.
It has to do not necessarily with a Manichean view of good and evil but a code of workable ethics.

Animal herd behavior depends on which animal. Human? It turns out that apes have a certain moral code. This is shown by behavioral studies. Check out Franz de Waal at Yerkes Primate Center. An interesting book is his "The Age of Empathy".

Evolution has to do with the ability to rationalize and determine what is moral and ethical.
The human brain has evolved to take care of this.

As to the survival of value systems, it depends entirely on what they are. The fact that we have value systems at all is evidence that Darwinian evolution has made us capable of this ability to create them. I can't prove it but it is possible that war is our specialization that could lead to the extinction of our species and this is certainly based on a value system.
Our ability to survive and adapt may depend on our ability to seek alternatives to war.

I think that war is immoral. It has been lauded and utilized by every religion in the world except for maybe Janism and some pacifist religions such as the Friends.

The "eye for an eye" quote is subject to a variety of interpretations. Wesley, yours is just one of them. Its usage today generally refers to revenge. It may not mean you should retaliate with violence but it does give you permission to do so.