Left Handedness

The occurrence of left handedness in humans has always been something that I find very interesting. Why are just under ~15% of humans left handed? Why not 50/50, it seems like it should be a random phenomenon if not just strictly 100% dexterity. There doesn't seem to be extensive studies on the subject, although to date what has been established is the high likelihood of "handedness" being a genetic trait. If this is the case, then it would be interesting to try to identify the gene which encodes for "handedness", I imagine if genetic, then it must be a recessive gene? I suppose that could be an explanation for the low frequency of left handed people.

I was doing some reading on the subject and found some interesting information, I have this friend who can practically explain how every word in the English language (well it seems that way to me since I don't know much about the stuff) has derived from Germanic, Latin, etc. influences, anyhow this kind of thing is right up his alley.
So I was reading on how the meaning of the term "left handed" has derived from extremely old words and how this is an indication that the infrequent occurrence of left handed individuals is a very old phenomenon. All of these words have some direct or indirect association with clumsiness, wrongness, evilness, etc. All characteristics which historically have been associated with the usage of ones left hand for various tasks.

For example, the word 'sinistral' has been used instead of 'left handed' and it is derived form the word 'sinister' originally meaning left in Latin but eventually during the classical Latin era took upon the meaning of evil or unlucky. The German word for left is 'links' and the adjective 'link' means devious, 'linksch' also means clumsy and 'linken' means to cheat, again these are all very old words.
In Portuguese 'canhoto' is a common word for left handed and at some point in the history of the language has been used to identify the devil. 'Venstrehåndsarbeid' is an expression for left handed work in Norwegian and has the meaning 'something that is done sloppy is incorrectly'. And the list goes on.
Alternatively all the words from which the term 'right handed' derive are also very old and have the opposite meaning as those which describe left handedness, that is correctness, rightness, authority, justness ('Mano derecha' in Spanish is the 'right hand', and 'derecho' also means correct and authority).