Evolution and the Origin of Morality

I take a very biological standpoint on the roots of human behaviors. I was taught throughout public school that animals' behavior in given situations is dictated solely by their DNA and their development up until the moment of observation. I would go on to say, furthermore, that (save complications like mirror neurons), an animal is limited in its reactions to its environment by its DNA. This is not easy to observe, as an animal's DNA is such a complicated code and development is so random (that is to say an animal's perception of its environment is so acute that even the most minute factors may have significant long-term effects on behavioral trends, which makes it impossible to prove empirically that there are no factors influencing animal behavior other than genetics, development, and current situation). However, I am going to assume that the following statements are true:

1. An animal's behavioral arsenal is dictated by its DNA.
2. The specific behaviors which occur in an animal are selected by the forces of its environment, past and present.
3. An animal's genetic code has been created by the forces of natural and sexual selection, with a few random changes (mutations)
4. Humans are animals.

If humans are animals, and animals behavioral arsenals are dictated by their DNA, and specific behaviors are selected by past experience and current environmental factors, and an animal's DNA is created primarily by natural/sexual selection, then human behavior is dictated, to a great degree, by the forces of natural and sexual selection.

Any geneticist or evolutionary scientist worth his weight in dog shit (or any more valuable commodity) will tell you that the forces of natural and sexual selection tend to create animals which are driven to maximize the number of copies of their genes in future generations to come.

If we assume that this vast body of scientists is correct in their belief, we can draw that the forces which have created us have created us so that our primary function is to spread copies of our genes in the next generation, the generation after that, etc.

In many species of animals, including humans, there exists a phenomenon known as reciprocal altruism. This phenomenon manifests itself in the form of animals being “nice” to each other (read: increasing each others' potential reproductive success) in exchange for the same courtesy. There are explanations as to how this phenomenon could have been created by the forces of natural and sexual selection, but I won't get into them. For further reading on reciprocal altruism, I suggest Richard Dawkins' The Selfish Gene. (Don't worry, it's from back when he was an empirical scientist.)

Let us assume that reciprocal altruism is “true”, and that it has evolved naturally.

I bet you're getting bored by now. I'll get to the point.

If a. human behavior is dictated largely by the forces of natural and sexual selection and b. the forces of natural and sexual selection tend to, in some cases, create seemingly altruistic animal behaviors such as reciprocal altruism and c. humans tend to communicate with each other in order to get their needs and desires fulfilled (I didn't provide backing for this premise, so if you disagree with it please mention so and I'll do just that) and d. it is generally beneficial, in terms of reproductive success, for a human to have altruistic behaviors performed toward itself by other humans (which it is. Again, I can back that up if you'd like.)

then it follows that humans would be likely to create a system of communication with the intention of promoting altruistic behaviors in other humans toward themselves. I believe that we already have, and we call it morality.

Thoughts? I have loads of implications to draw from this conclusion, if anyone is interested.

Edit: Thanks for all of the replies, guys. It's relieving to learn that this does in fact make some semblance of sense, as I've bounced it off many people in real life only to find that they either didn't understand, disagreed entirely, or just didn't care. Thanks also for the corrections and recommendations.