What would be the harm?

[Angrboda]

Exactly, jorm.  Exactly.  It's very advantageous to me from the standpoint of evolutionary biology (hell, it's advantageous to the species), and yet, as a moral proposition....wrong.  Is that not out-thinking our biology, or unmooring our moral propositions from an evolutionary underpinning that may not describe "the good" only the "good-for"?

Oh, gotcha. I thought you were suggesting burning out our neighbors was a moral proposition. Now that I understand, allow me to object to what you meant. As an individual act, burning out my neighbors has advantages. However if I further a world in which people are allowed to burn each other out ad libitum, then that threatens the security and safety of me and mine. I have a definite biological interest in the safety of me and mine, so I have a biological motive for forbidding such things, and refraining from them for fear that doing so might prompt others to do likewise to me, regardless of how advantageous it might be for me to act thus otherwise. So, no, this is not an example where morals are in contradiction to evolved needs and biology. The problem is the lack of universalizability of the act. An act which is in accord with my interests can quickly become contrary to my interests if universalizing said behavior would impinge upon the survivability of me and my genes. This is why most moral frameworks, such as Kant's, have universalizability as a key feature. Same goes for pillaging. Rape is a slightly different animal. It has similar drawbacks, especially since universalizability of rape would yield a world in which I was likely inefficiently spending my resources raising someone else's seed, a situation which is directly opposed to the interests of my genes.