Question: Why is there 2 genders?

Alessandro Guazzi answered on 12 Mar 2013:

Very good question!

There are several reasons that make having 2 genders a good idea. The first is that you get more chance of change, and so can adapt faster as a species, because you’re inheriting genes both from your father and from your mother. This would not happen if a species were to clone itself every time, like some plants, who are in fact very much at risk of being wiped out by only one disease!
The second reason is that the division into two genders helps species survive because the two genders are generally specialised to do different things. Females are generally specialised at nurturing the offspring and protecting it, while males are generally specialised at providing stuff to eat and protection for the family as a whole.
Some weird cases are a good example: some female spiders eat their mates after conception, and this makes the birth of the offspring more likely! In this case the male quite literally provides the food: himself! Yuck!