Throughout most of the animal kingdom, parenting does not occur. In "lower animals," up through amphibians and reptiles, fertilized eggs and live young are cast into the world, expected to fend for themselves. With few exceptions, parenting is limited to birds and mammals and, for the most part, it is a maternal responsibility. Encompassing efforts to feed, protect and instill survival skills, the process may take weeks to years, depending on the species.
In mammals, females are instinctively equipped to nurse, protect and teach their young; failure to do so generally implies underlying illness (physical, mental or emotional). In some species, males may take part as providers and protectors but, as we all know, their dedication to these responsibilities is far from reliable. Early humans, like other primates, were likely polygamous and the male's attention to individual sons or daughters was surely lacking. As human society advanced, monogamy has been encouraged through a variety of legal, religious and social pressures and, as a consequence, fathers have taken a more active role in parenting.
As all parents discover, their role is both the most rewarding and the most difficult of human experiences. Due to our large brain, which consumes a large portion of our caloric intake, human children mature very slowly and, though physically capable of producing offspring within fourteen years or so, they require significant parenting themselves for at least two decades. Efforts to prepare them for survival in the modern world is far more challenging than it was in the early centuries of human history. Life, while much easier in some ways, is far more complex in others. Nevertheless, good parenting still comes down to the capacity to love, nurture, protect, teach and let go.