The idea that someone out there was made just for you is not a new one. The saying may have originated with marriages that were arranged at birth and the children thus influenced into the attraction. However, there is something to be said about nature's way of influencing our decisions to find a mate. There is plenty of evidence suggesting that nature has a secret plan for what we do or do not find attractive. Broad shoulders on a man, or round hips on a woman are just the obvious qualities to mention about attraction. More subtle have to do with the "magic number" theory that deals with facial construction or as peculiar as finger length. The question is, does genetic attraction equate to this? Since a person's features have been proven to lie in their genetic code; To say that natural attraction is the same as genetic attraction is not unfounded.
Genetic sexual attraction is a more scientific term for incest. Although the practice was encouraged in earlier humans in order to save the species by procreation, there is no need for incestual relationships in contemporary society. Genetic sexual attraction is a perversion in every sense of the concept because it implies the best sexual partner is someone in your own family. Genetic differentiation is the key to survival, so it is important to marry outside your own family if humanity is to survive over the long term.
I believe these two forms of sexual attraction are really the same thing. Genetics and nature are both things we're born with and cannot change. A predilection for one type of partner over another is not a choice, in my opinion, but something we're born with. Nature does not win out over genetics.
I personally think that genetic sexual attraction can not be considered perversion of natural sexual attraction because genetic sexual attraction comes within two people and they have to have some sort of communication. I personally think that natural sexual attraction comes from the two people without making any decisions and just doing whatever that satisfies the other person.
When it comes to sex and sexuality there is usually no two people who feel exactly the same. Everyone has their own things that turns them on, and those things could completely repulse another person. While I would never have any sort of intimacy with a relative, I do not believe it should be considered a perversion of natural sexual attraction. Perversion is too broad of a term and can too many meanings.