The Fingerprint of God

In a material, dog-eat-dog world where pain and suffering exist and where only the fittest survive, how and why did selfless love appear? How did love become one of the most basic necessities of human life? What exactly is love anyway? Is the existence--and necessity--of selfless love evidence that we really were created in the image of a loving God? What if love was God's fingerprint on our world and in our lives? What if love was the proof that he was here and that he made us to love and be loved?