Yeah, I expect this isn’t going to be how that sort of mechanism works, but it’s always been an interesting concept for me, that while “genetic memory” as presented in much fiction is extremely unlikely just from the sheer entropic hill such mechanisms would have to evolutionarily climb to be able to pass on so much information (on top of the baseline necessary information for reproduction, the majority of memory won’t on average confer a lot of reproductive advantages, so it’s statistically more likely to get optimised out by the random mistakes of evolution, hence entropically “uphill”) …

Yet while this fictional form is unlikely we have quite a lot of good examples and evidence for “inherited information”. You have to be careful with it since it’s too easy to accidentally include side channels for organisms to learn the information and thus break the test. Such as insects being genetically driven towards food by smell at a molecular chemical interaction level, and the smell becoming associated with the information you wish to test. A bee colony can’t be reliably tested unless you raise it from a new queen in an odourless environment if you wish to see if bees genetically know that the shape of a flower is associated with food. It’s tough to subtract the potential that a colony will have learned and “programmed” later generations of bees with things like the classic waggle dancing in order to more efficiently gather food.

We do have good ones though like cats and snake shaped objects, it’s surprisingly consistent, and pops up in some other animal species. It’s wired into our brains a bit to watch out for such threats. There’s a significant bias towards pareidolia in human brains and it’s telling how deeply wired we have some of these things, but it is there and study shows it seems to form well before our cognitive abilities do… these all have some obvious reproductive advantages however so it makes sense that the “instinct” would be preserved over generations as it confers an advantage. But it’s still impressive that it can encode moderately complex information like “looks like the face of my species” or “cylindrical looking objects on the ground might be dangerous”… even if it’s encoded in a lossy subconscious instinctual level.

> But it’s still impressive that it can encode moderately complex information like “looks like the face of my species” or “cylindrical looking objects on the ground might be dangerous”… even if it’s encoded in a lossy subconscious instinctual level.

I think it helps that the encoding does not have to be transferable in any way. This kind of "memory" has no need for portability between individuals or species - it doesn't even need to be factored out as a thing in any meaningful sense. I.e. we may not be able to isolate where exactly the "snake-shaped object" bit of instinct is stored, and even if we could, copy-pasting it from a cat to a dog wouldn't likely lead the (offspring of the) latter to develop the same instinct. The instinct encoding has to only ever be compatible with one's direct offspring, which is a nearly-identical copy, and so the encoding can be optimized down to some minimum tweaks - instructions that wouldn't work in another species, or even if copy-pasted down couple generations of one's offspring.

(In a way, it's similar to natural language, which rapidly (but not instantly) loses meaning with distance, both spatial/social and temporal.)

In discussing this topic, one has to also remember the insight from "Reflections on Trusting Trust" - the data/behavior you're looking for may not even be in the source code. DNA, after all, isn't universal, abstract descriptor of life. It's code executed by a complex machine that, as part of its function, copies itself along with the code. There is lots of "hidden" information capacity in organisms' reproduction machinery, being silently passed on and subject to evolutionary pressures as much as DNA itself is.

Oh absolutely... and that's a great analogy for the more computer oriented, "Reflections on Trusting Trust" highlights how it can be the supporting infrastructure of replication that passes on the relevant information... a compiler attack like that is equivalent to things like epigenetic information transfer... and for fun bonus measure since it came to mind... the short story Coding Machines goes well for really helping to never forget the idea behind "Reflections on Trusting Trust" https://www.teamten.com/lawrence/writings/coding-machines/

It definitely would be minimised data transfer, be it via an epigenetic nudge that just happens to work by sheer dumb luck because of some other existing mechanism or a sophisticated DNA driven growth of some very specific part of the mammalian connectome that we do not yet understand because we've barely got the full connectome maps of worms and insects, mammals are a mile away at the moment... no matter the mechanism evolution will have optimised it pretty heavily for simply information robustness reasons, fragile genetic/reproductive information transfer mistakes that work, break and get optimised out in favour of the more robust ones that don't break and more reliably pass on their advantage.

You need to compare that with an alternative solution where this information is learned by each generation and then asses the survival advantage of having it encoded in DNA. This is outside my field and I don’t have a strong opinion.