Right, but some of this (such as orgasm = war = genetic melange) stuff isn't exactly an attempt to project modern science into the future. At least I don't think so.
I think it's an extrapolation of a serious scientific suggestion. It could well be related to group selection, which was very in vogue back then because Hamilton and the other Neo-Darwinists hadn't yet demolished most of the claimed 'examples' of group selection and demonstrated the narrow range of conditions required for it to operate. But it's hard to tell because Walter's book is very
obscure: the only copy I can find online is $200, the original book reviews I've read are very cursory, and judging from the void online, no one's read it in the past 40 years. So when Leto II talks in GEoD about war being orgasm and the necessity for the Fish Speaker army to be an all-female army, it's hard to know to what extent this might just be a weird version of or copying Walter's ideas or Herbert engaging and extending Walter's ideas as an enthusiast of it (maybe Walter suggested that male armies inherently tend towards aggression for pent-up sexual and reproductive needs, in which case an all-female army might correct that bias, and be feasible in a modern automated war; or maybe that's Herbert's own reply to the problem Walter identifies, and is in fact supposed to be a key mechanism in why Leto II's reign is so stable and peaceful).
And just recently as a matter of fact I've read about evidence that organisms seem to actually be able to pass on knowledge other than what is strictly encoded in their DNA. In other words, things that happen during their lifetime appear to be able to be transmitted to offspring. How or to what degree, we don't know.
I wouldn't overstate our ignorance here... There's a lot of popular faddishness around epigenetics, especially wild theorizing about transgenerational non-genetic/non-environmental inheritance mediated via epigenetics (http://www.wiringthebrain.com/2018/05/g ... al-of.html
). The real role of epigenetics is usually much more humdrum: they're simply part of the usual machinery for translating genes into useful effects inside the organism - effects, not causes. Transgenerational epigenetics doesn't even make much sense from a theoretical point of view as I think Hamilton, actually, has pointed out: it needs to encode information which is adaptive (or else there's no point and the epigenetic marks will be erased at fertilization like all other epigenetic marks usually are), but not on a many generational timescale (or DNA is much superior) but also not within a generation (where neural and other learning mechanisms are much faster and more reliable and adaptive) and the environmental fluctuations need to repeat regularly but not too regularly or else more special-purpose mechanisms will evolve. Not to mention the difficulty of postulating the machinery to take specific environmental effects, transcribe them into sperm/egg DNA, survive fertilization and growth etc, and have some desirable effect. (It's not quite as bad as the theory in the pseudoscience Left in the Dark
explaining how eating fruit caused humans to evolve: eating fruits causes steroids, which then change DNA - don't ask for details of how that works! it just happens! - which then leads to more fruits and intelligence... But still pretty bad.)
Likewise about other matters in the book, such as the Holtzmann technology
I have definitely run into nothing that looks like an inspiration for those, and I think they were simply your usual handwavy SF advanced-tech, with no interesting background or implications. (They also are less interesting and discussed much less, perhaps for that very reason.)
I'm certain that he didn't just transplant Yoga and have the BG be Yoga practitioners.
I think they are, in the same way that the Zensufi mystics are practicing Zen meditation or the Orange Catholic Bible is Christianity & Islam etc. That is, they are practicing an advanced form of yoga developed over thousands of years and eclectically merged with other disciplines by the BG.
I think FH in particular took a very particular approach to 'telling truth' where he believed in alluding to it rather than stating it verbatim. He seemed to prefer to present a mystery to make the reader think rather than just telling you what he thought, using the book as a thinly veiled mouthpiece (as Simmons seems to have done).
Oh, of course Herbert isn't going to just state it bluntly. The surest way to be boring is to reveal everything to the reader. How much less interesting is Lord of the Rings
after you've read the Silmarillion
and understand all the allusions and references? Herbert definitely is doing the obscurity deliberately - Leto is deliberately infuriating to make the reader think and feel confused. Actually, you can see this process in the Dune drafts: Touponce includes a photo of the Dune Messiah
draft of one of Paul's monologues, and notes that the draft version is very blunt, crude, straightforward, and boring, while the final published version is full of back and forth and question marks and subversion, and is much more interesting to read (and harder to understand).