I have a question for the OP (@Dominic2090), which I hope was not already addressed in the aforementioned Part 1. And allow me to reveal from the outset that I am a Bible-believing evangelical Christian who accepts the science and history of evolution within a biblical world-view.
Let us suppose for the sake of argument that some animals do have a capacity for rudimentary moral behavior. Given this fact, what kind of problems do you anticipate?
“Can we say that a chimpanzee is morally culpable to his troop for some wrongdoing?” Well, let us assume for the sake of argument that he is. What, specifically, would be the problem with that scenario?
“Is he morally culpable before God?” I don’t see how, as there are no creatures on Earth with whom God has a covenant relationship other than humans. I am willing to grant that some animals are capable of wrongdoing and may be morally culpable to those in their community, but that wrongdoing cannot be a sin against God without a covenant relationship defining that term. This would make a distinction between moral wrongdoing and sin, the former representing a horizontal dimension (morally culpable before others) and the latter representing a vertical dimension (morally culpable before God). Humans are not unique with respect to the former, but they are with respect to the latter.
As far as I can tell, it would seem to follow from the biblical witness that there is no such thing as “sin” apart from a covenant relationship with God. No creatures on Earth other than humans are either capable or culpable of sin, despite the fact that other creatures demonstrate characteristics of moral agency—a state of affairs which could arguably apply to humans prior to a covenant relationship with God (i.e., before Adam). That is, before Adam and the garden, humans were capable of wrongdoing but not sin, a term which was meaningless until the events of the garden. Once that covenant relationship was established, however, sin became a potential—but not an actuality until Adam disobeyed God (thus Adam’s state of posse non peccare et posse peccare is preserved).