Where does this love come from?

Where does this depth of love come from? How am I so connected to Ani? Why do we experience so much grief? It's seems unheard of in the rest of the animals on earth. I think it really comes from God, why would natural selection give parents the extended grief that comes from losing an offspring? What would it really matter if a calf or a baby bird died? Does it really affect their parents survival? I think that we, in God's image, have a hint of his love, and we continue to remember our lost children until we can see them when we pass on. I only pray that we could more easily draw upon and understand this depth of love for each other, and let it drive us.