Re: Pair of male & female
There are lots of animals (male) who kill and eat their offspring when hungry. Then what?
Are you going to use this as standard of right or wrong too?
That reminds me of a cartoon I had on my work window:
Four lions playing cards and in background lionesses are chasing a zebra.
One lion says:
What do you say guys, should we take a break for lunch now? 
Anyhow, the gender role for human which OP or other people is talking about is different than you mentioned.