Bolder-dash writes:
I understand, you don't feel anything about a chicken, and won't mind what happens to it. But if you have to grab the chicken, and twist its neck to break it, and listen to it, will that bother you? What if it was a cow instead of a chicken, and you needed to hit it in the head with a hammer to kill it-feel anything? A horse?
The horse should be the same as smashing a rock to you, if this is all just about your own ability to pass on your genes.
The further you take this line of thought, the more unpleasant each stage becomes - to a human being. You are correct that if I had to twist the chicken's head off myself, I would find it a less than pleasant experience. That is
not evidence that a supernatural being gave me the morality that makes such a thought repugnant. It is only evidence that we with our larger brains and complex social structure have developed guidelines which we (mostly) adhere to, called morals.
Modulous writes:
It does appear that we are like beasts, capable of creating social strategies and navigating the various challenges that come our way.
I agree wholeheartedly with this, but would extend it a step further to say that we ARE beasts, and the only thing that separates us in these respects from other animals is a long history of intelligent debate about exactly what is right and wrong. The "moral zeitgeist" is a shifting one - what is considered moral by 16th century standards might well be considered reprehensible by today's.
As others have pointed out as well, morals are not black and white.
You may have heard of Hauser's moral dilemmas.
In one hypothetical scenario there is a runaway trolley on a railway line which threatens to kill five people. If you were in a position to divert the trolly onto a siding thereby saving the lives of five people, you would undoubtedly do so. But what if the only place you could divert it was onto a siding where one old lady would be killed? Would you divert it, thus saving 5 lives and killing 1? Many can agree that, as horrible a decision as this is, it would be the right thing to do. (I'd like to hear a fundamentalist's response, as I suspect that in their mind the act of diverting the train and killing the 1 is murder, a violation of the ten commandments.)
Similarly, there are 5 patients in a hospital who need organs with haste or they will die. In the waiting room is a healthy young patient with a minor ailment who happens to be the right blood type to serve as a donor to the previously mentioned five. Would the doctor be making a "moral" decision to forcefully execute the one man in the waiting room and take his organs in order to save the 5 in need? Of course not... this would be murder.
As the specifics of these conundrums are expanded upon, there is more and more uncertainty as to exactly what the most "moral" course of action would be.
For a thorough treatment of the Darwinian origins of altruistic behaviour you should read "The Science of Good and Evil" by Michael Shermer. Likewise there is a chapter in Richard Dakwins's "The God Delusion" that discusses Darwinian rationale for morality. In that are listed no less than four Darwinian bases for altruistic behaviour.