If you are asking about why God does it that way, and not the scientific explanation, it is to provide a means with which to separate the good from the evil of the Spirit, the Light from the darkness.
With asexual reproduction you would only get clones, the Spirit in its entirety would be passed on. But with sexual reproduction you get a unique individual, with a unique soul, and its own unique part of the Spirit.
Those unique parts of the Spirit will be either of the Holy Spirit, or not.
The Holy of the Spirit in Man is what goes on to become the Bride for the Bridegroom Jesus in the Son of God.
It is the way to ensure that the physical Creation of God is perfect through the perfecting of the Spirit.
Agreed, that does make sense to say something of that nature. Therefore, I shall provide a scientific explaination to go along with the posts of others:
Why do we not reproduce asexually?
It is actually a very simple matter, although not obvious on the surface. If we were to reproduce in such a fashion, there would not be a great deal of variation; biodiversity in the species, if you will. The survival of our species depends on the fact that we
are unique individuals. Without such, one good plague would kill us all off, for there would be few who could resist it, as we would continually genetically pass down similiar genes. The (random and usually harmful, when you do not view it in the context of the situation) mutations that we are given allow us to branch out in our diversity. Thus, we can survive as a species, for the variations amongst us allow us to remain seperate from one another, thus allowing for varying advantages and disadvantages (depending on the context of the situation).
Let me give an example:
We have a population of... lets say village idiots. Now, each of these village idiots, although they all provide a psychosocial service to the community by giving people someone to ridicule, each vary in their style of foolishness, and the degree that they are foolish in nature.
Thus, we have several groups:
Those who rely on slap-stick comedy and do it occasionally.
Those who rely on slap-stick comedy and do it constantly.
Those who rely on practical jokes and do it occasionally.
Those who rely on practical jokes and do it constantly.
Those who rely on rabbits and use them occasionally.
Those who rely on rabbits and use them constantly.
This is the many types of blundering half-witted troglodytes that we have with us in the little town. However, the villagers are picky on their type of comedy that they listen to, and only accept certain variations.
For example, the community likes practical jokes, hates rabbits, and can stand lightly done slap-stick comedy.
Thus, the unacceptables are 'not laughed' out of the village, leaving the following groups:
Those who rely on slap-stick comedy and do it occasionally.
Those who rely on practical jokes and do it occasionally.
Those who rely on practical jokes and do it constantly.
Now, the village idiots we have can now flourish. However, if there was no variation, they may have all been kicked out of town, leaving in their wake a mass of bored villagers. With no comedians, the villagers would have to make up their comedy, thus we would find them entering the idiot zone...
See here..
http://malakoff.com/idiot.gif
This sums up why we need this variation.