Is there a "mom gene"?

In Charlotte Perkins Gilman's story, "The Unnatural Mother," she writes about a woman who, from her home on the edge of town, observed a dam about to break, which would have the power to sweep away 3 villages in its wake.  So this woman ran full-force from her home down to the town, delivered the news, and the lives of the residents of all 3 villages were saved.  Immediately upon delivering the news she ran back to her own home to retrieve her only child who was...

Although this story is myopic in scope, it begs the question, what does "maternal instinct" mean?  Is there a "maternal gene"?  Richard Dawkins wrote of "the selfish gene" (a biological view of genes that ensure survival as well as....