To understand we must first know ourselves. It's meaningless to do anything without a reason. All help we offer each other can be explained as self help, even if it's to go to heaven or avoid hell. We see a wider/deeper world than the chimps, therefore we do everything wider/deeper. It has no moral and extra meaning. I think the best I can say is I'd help a chimp more than a tree, a tree more than a blade of grass. But being in competition with other humans things get a bit more complicated.