OskarStaleberg, I definitely agree with your comments to an extent. Especially this, “It’s beneficial for the individual to get along with the group, and it’s beneficial for the group not to kill and steal from each other.”
But I think the solely evolutionary view of morality falls short because it concludes that nothing is OBJECTIVELY right or wrong. As you say, “right and wrong are only matters of perception.”
The problematic question you then have to answer is: upon what basis can we declare any action RIGHT or WRONG?