Nice thought.
Just a warning: when talk about human evolution and make distinctions between human parents who take care of their children and parents who don’t, you are taking a dangerous path.
Human beings are not created from nothing, in fact we are the product of an evolution that started some billions years before.
As you state in the article, even animals take care of their pets, so the real origins of this feeling come from long time before the first Homo Sapiens appeared on the Earth.
But if we talk about the origins of Love as a feeling, and not an instinct, then we need to take a step further...
We feel Love thanks to a feature only Human Beings have, as far as we know, that is self-awareness.
We are conscious that we are conscious.
We not only feel the need to take care of our children: we are also aware of it.
And when we add an extra layer to our life, then we have more chances to have it broken, as many other layers may overlap this feeling.
That is, there are many parents who don’t take care of their children and let them die, a feature sadly unique to Human Beings.
RE: Today’s lesson: Why do we feel love? What is its origin?