Eli5: how is it that so many species, including humans, have the same motherly instinct that suddenly appears after birth? Where does this come from?

Question

Eli5: how is it that so many species, including humans, have the same motherly instinct that suddenly appears after birth? Where does this come from?

In: 2

Answer 1

At the basic core of any living organism, is the instinct to reproduce and create future offsprings to continue the species. That means the parent must have the drive to protect their some of their offsprings in certain ways that some of their offsprings make it to reproductive age.

Now, instinct is a complex behavior exhibited in response to certain stimuli. Our behavior comes down to chemical processes in the brain. So in response to certain stimuli (babies crying), it triggers a hormonal response in the brain to tend after the babies.

Now, where on our genome that encodes specific behaviors, is largely unknown,