> I've started to think that expecting armageddon is an innate part of human psychology.
Sci-fi novel plot starter: it's a quality that has been selected for by interstellar progenitors who seeded life on Earth, so that we would be wary of the need to mitigate real planet-scale disasters.
I've seen this used as a plot seed for any number of space operas, but as far as I can recall, I haven't seen any that used it and also explained how they were able to somehow instill traits which, over hundreds of millions or billions of years, could not only remain present but unexpressed in the genomes of Nth-generation offspring, but could then, in response to some kind of extremely specific and complex stimulus, be expressed - but only when needed, and in perfect accord with the original intelligent design.
It sounds like I'm making fun here, and I'll admit I picked the phrase "intelligent design" with puckishness aforethought. But it's a serious question, and what I'm really looking for is media recs. Does anyone actually reckon with this, in a way that's plausibly compossible with our current understanding of genomic heredity?
(Introns and pseudogenes don't count, and yes, I remember that hilarious TNG S6 episode that used them as an excuse to give Barclay even more not-very-well-depicted psychological problems. Sure, these regions aren't translated into proteins, but they remain as susceptible to all the ordinary mechanisms of mutation as any other part of the genome. Not only that, being unexpressed, they are if anything less likely to be conserved than exons, so the "alien space magic hidden in non-coding DNA!" thing doesn't fly.)
Easily. Make the genetic machinery responsible for the trigger hideously complex, redundant and, if possible, self-repairing (perhaps via a gene drive), and have loads of other genes rely on specific bits of it, so that a single alteration in that machinery will make life suck for the mutant without much preventing the trigger.
Evolution can't make big changes, because there is no guiding intelligence behind it, only statistics; that's why our retinas are still backwards, and why a giraffe's laryngeal nerves take five metres to connect points ~30cm apart. Even though life without this massive lump of “junk DNA” that everything seems to rely on would work better, evolve faster, thrive more, waste fewer resources, reproduce more efficiently… it'll take a lot of mutations for it to unravel, none of which are selected for. Parts of it might get corrupted by sheer fluke, if the corruption also disables each anti-corruption mechanism and happens to coincide with a beneficial mutation, but that's what the redundancy's for.
How does anything "rely on specific bits of it" if it's noncoding? How does the gene drive remain intact across millions of generations' worth of mutation events? How are mutations in noncoding DNA selected against?
One way would be to apply selection pressure over time and let the people experience "numerous tribe-ending disasters" as one other commenter said.
Then there is no need for these "Precursors" in this theory, it could very well just be all natural.
Sci-fi novel plot starter: it's a quality that has been selected for by interstellar progenitors who seeded life on Earth, so that we would be wary of the need to mitigate real planet-scale disasters.