Sam, you are wrong on much of your post.... there are kernels of fact in there, but then you start to attribute it to God instead of actual verifiable information. Boots et. al. covered the evolutionary benefits pretty well so I'll leave those stand on their own merits, but a couple other quick points.
First off you mention moral absolutes. Murder is really the only moral absolute that is cross-cultural and cross-temporal (theft is usually a close second). All other things, rape included, are dependent on the era and the culture. The Bible itself ADVOCATES RAPE.
Moses, Eleazar the priest, and all the leaders of the people went to meet them outside the camp. But Moses was furious with all the military commanders who had returned from the battle. "Why have you let all the women live?" he demanded. "These are the very ones who followed Balaam's advice and caused the people of Israel to rebel against the LORD at Mount Peor. They are the ones who caused the plague to strike the LORD's people. Now kill all the boys and all the women who have slept with a man. Only the young girls who are virgins may live; you may keep them for yourselves.
As you approach a town to attack it, first offer its people terms for peace. If they accept your terms and open the gates to you, then all the people inside will serve you in forced labor. But if they refuse to make peace and prepare to fight, you must attack the town. When the LORD your God hands it over to you, kill every man in the town. But you may keep for yourselves all the women, children, livestock, and other plunder. You may enjoy the spoils of your enemies that the LORD your God has given you.
If a man is caught in the act of raping a young woman who is not engaged, he must pay fifty pieces of silver to her father. Then he must marry the young woman because he violated her, and he will never be allowed to divorce her.
Thus says the Lord: 'I will bring evil upon you out of your own house. I will take your wives [plural] while you live to see it, and will give them to your neighbor. He shall lie with your wives in broad daylight. You have done this deed in secret, but I will bring it about in the presence of all Israel, and with the sun looking down.'
2 Samuel 12:11-12
They must be dividing the spoils they took: there must be a damsel or two for each man, Spoils of dyed cloth as Sisera's spoil, an ornate shawl or two for me in the spoil.
When a man sells his daughter as a slave, she will not be freed at the end of six years as the men are. If she does not please the man who bought her, he may allow her to be bought back again. But he is not allowed to sell her to foreigners, since he is the one who broke the contract with her. And if the slave girl's owner arranges for her to marry his son, he may no longer treat her as a slave girl, but he must treat her as his daughter. If he himself marries her and then takes another wife, he may not reduce her food or clothing or fail to sleep with her as his wife. If he fails in any of these three ways, she may leave as a free woman without making any payment.
Lo, a day shall come for the Lord when the spoils shall be divided in your midst. And I will gather all the nations against Jerusalem for battle: the city shall be taken, houses plundered, women ravished; half of the city shall go into exile, but the rest of the people shall not be removed from the city.
For a moral absolute. God seems pretty okay
with rape my friend.
Murder is a pretty obvious one too as it removes someones genes from the pool. I am not going to go too much into this because if I have to explain why murder is wrong, we have issues.... but even something like murder God advocates literally thousands if not millions of times over in the Bible. "The Flood", Genocide, dashing of infants against rocks... ALL advocated by your moral authority Sam. Its uncomfortable but true. (this is going to sound dickish, and I apologize beforehand) - By all means, start the thread on the Bible being the God-breathed infallible word, Im sure this community will enjoy it.
If you haven't already, read Anfauglir's point about greater brainpower. Surely you understand that since our species is capable of abstract thought this lends ourselves to empathy at a greater distance (ie. donating money to AIDS patients in Africa) than other species.