But some of the powers, like remembering ancestors memories barely even exist in humans today. The field of epigenetics has proven that a starving parent can alter how the genetics of even grandchildren express themselves. So some basic functions like wrapping DNA tighter or loser and adding a methyl chemical group exist to pass information across generations, but this is like an extra bit or two per gene. To extend the functionality to the level of recording memories would take almost as long as it took for DNA to become as fancy as it did from the original RNA molecules that could produce more of themselves without any enzymes or DNA having developed yet. So almost as long again as life itself has taken, not 20 years.
That would be a valid point... except why are they still breeding for things like intelligence? That was my point. Thousands of generations later, they're still breeding for basic stuff like enhanced intelligence, which makes little sense under pretty much everything we know about intelligence's genetics.
> The field of epigenetics has proven that a starving parent can alter how the genetics of even grandchildren express themselves.
The extent to which transgenerational heritable epigenetics matters in humans has been wildly exaggerated by the media and the field is rife with overinterpretations, small samples, and non-replication.
Not to mention, even that hype didn't exist when Herbert was writing it, so he couldn't've been thinking of it. I am fairly sure he was gesturing towards a more Akashi-Records-style psi mechanism with access granted by ancestry, not actual encoding of memories into spare DNA (which among other things would mean no ancestor would remember anything after having a kid).
> To extend the functionality to the level of recording memories would take almost as long as it took for DNA to become as fancy as it did from the original RNA molecules that could produce more of themselves without any enzymes or DNA having developed yet.
Neurons already re-edit and splice their chromosomal DNA, so the mechanisms are already there for at least part of it.
If you could determine with 99% accuracy the exact genome of a child by their parents genomes alone, would you be able to optimize humans across given a relatively small set?
Also "wild genes" - particularly those of the Fremen - producing unexpected results (ex: Leto II).
The Bene Tleilax though, they're probably making solid genetic projections.
This leaves aside the more important question raised by the scope of the Dune universe, which is defining what 'optimal' would even mean in such a world. Traits are only optimal or sub-optimal relative to an environment. Being smart and not able to move heavy objects would doom a medieval man, but being stupid but strong would hamper a modern man. That's a facile example and you'd be more likely talking about weakness to certain pathogens, dependence upon particular physical environmental needs (oxygen level, caloric availability, body temperature control efficiency, etc) though, really. If you're going to be planet-hopping and galavanting across the universe, what is optimal in one place can kill you in another and vice versa. The myth that there is a 'strongest' state is just that, a myth.
In genetics, diversity always wins. Flexibility and complexity always wins. Being mediocre at everything is a far greater survival trait than being a master at one is if it means you are a total failure on another count. Living things can only fail once.
Furthermore, one can now ask if the more perfect specimen for a given environment might be a chimera: this genome for nervous system, that genome for leg muscles, this other genome for internal organs, etc.
But your main point stands. The Dune series presumes that such a thing as breeding a superior human is not very difficult to manage on the scale of mere centuries. I am not sure how even define such a thing. And I rather doubt such a specimen would breed true with a similarly superior specimen.
Writers that take your approach - it’s all made up so I’ll just make up new rules whenever so feel like it - are rarely satisfying because the reader can’t trust anything or reason about the setting or the characters choices.
This is the problem with J.J. Abrams approach Star Trek and Star Wars. He seemed to take a special glee in arbitrarily violating established conventions in the settings with respect to things like how Warp Drive and Transporter technology work in Star Trek.
I have noticed, however, that in _My Little Pony_ (which I've finally gotten around to watching), it seems like earth/pegasus/unicorn traits are not races or subspecies analogous to human races but instead likely follow a polytomous liability threshold pattern. Why? Because we see the Cakes, two earth ponies, manage to have a pair of pegasus and unicorn fraternal twins, and when queried, mention they have some pegasus/unicorn ancestry. Since the pony type is mutually exclusive (we never see any pony who is both pegasus and unicorn, aside from the alicorns who are special magically-created cases), I don't know of any kind of common Mendelian trait pattern which would give a single type, normally breed true, and allow two earth pony parents with mixed ancestry to have kids who are both unicorns and pegasi (one non-earth-pony offspring would be fine as it would simply indicate a recessive discrete trait, but two different others? I don't see how that works unless you postulate some sort of multi-locus Mendelian trait with dominance of earth trait by both unicorn and pegasus, I guess?). Whereas if it's polytomous liability threshold, then that would be possible albeit unlikely, since they could inherit different fractions of ancestry and get pushed across different type thresholds.
In the Dune case a very Mendelian concern with preserving a few important mutations in very narrow bloodlines could be combined with a secondary requirement for high IQ, physical fitness etc. that could be (inefficiently) satisfied by focusing on "well bred" aristocracy that benefits from marrying genetically far above average people.
With regard to the X-Men, I think they imply the "present day" is a Cambrian explosion, that then settles down in the far future into the most useful powers becoming common if less godlike levels: immortality, psi, telekinesis, and any other boring wish fulfillment.
However, in the cases where the mutation seems to not be directly inherited, the explanation lies in the "implementation details", as it were. When the X-gene activates (due to puberty, stress, etc.), it releases a protein that goes on to cause mutations in surrounding genes, seemingly at-random but not so random that you have "mutant" teens dropping dead of sudden protein deficiencies.
the main plot is an alegory of all the wars USA entered so oil prices remained under control.
the oil must flow.
Full disclosure: I didn't enjoy the Brian Herbert stuff.