system
Given the following post, respond as if you're commenting on Reddit:
human
How / Is domesticated behaviour carried into genes ?

Most dogs are friendly to humans. I assume this comes from a long term mutually beneficial relationship since prehistoric era. How that familiarity is passed through generations (if it is) ?

Is every dog a "subwolf" that need to be updated through training that Human is the alpha etc...
Or they already "know" us and are genuinely symbiotic (For the lack of other words) to us ? 

same could be applied to horses and cats. But dog feels like a prime case.
gpt
The short answer is that nobody will give you a list of friendliness or domestication genes (sections of DNA). What we see is a pattern of domestication over many generations; humans would selectively breed the friendlier or less vicious wolves and gradually the dogs we know today were born.

This was done in a small number (<50 or something) generations of Foxes in Russia, using a more aggressive selective breeding program.