>>Does the Detian genemod rewrite the DNA of 1st generation offspring to
>>ensure that the trait is carried forward (thus effectively making all
>>children of Detian parents 1st generation offspring, at least from a
>>Detian genetic standpoint)? Or is there something else at work here
>>(such as DITTC)?
>
>Sort of both. I mean, keep in mind that as a fictional device, it was
>invented by a bright high school student, not a practicing geneticist.
> It doesn't get "watered down" in successive generations, even if both
>parents don't have it; it either of a person's parents is a Detian,
>that person will be as well. The only functional difference for a
>"first generation" recipient is that they weren't born that way.

Detiains wouldn't be the only fictional race with an "overwrite" system for parts of the genome.

Chakats<1> have something similar as part of their ability to interbreed with just about any canid or feline centaur. Key parts of the DNA received from the non-chakat parent are overwritten in order to have the resultant child also be a chakat.

<1> http://www.chakatsden.com/chakat/Intro.html