Where does your desire come from?

I am the product of an evolutionary process. All my ancestors actively took steps to preserve their inheritance.

Fallacy. Very few people have a *conscious intention* to preserve their genes.

Because a trait is rare it does not follow that it does not have a genetic basis. Besides, the basics of this trait are not especially rare: plenty of people want their descendants to flourish.

Of course, this trait - like every other aspect of me - is also the result of a complex developmental process, including interactions with the environment. That is just basic biology.

What DNA are you loyal to?

I do not always see myself as a single unified entity. Rather, I am a collective being - pulled in different, and sometimes conflicting directions by different genes - so: there is not necessarily any single unified "I" to which the "you" in your question refers. As with all organisms, my genes compete with each other to control my body. It's mostly a benign competition - often likened to a parliment. However, conflicts of interests can occur - in which case which gene gets the upper hand depends on the details of the circumstances.