> For me, it's a mystery.

For me, it's one of the last true mysteries! We've figured out damned near everything else, nothing has this level of "unknown" to it.

It's simply mind-blowing to me how such a tiny block of data can encode such high-level behaviours so indirectly!

Genes code for proteins, not synapse weights!

Those proteins influence cell division, specialisation, and growth through a complex interplay of thousands of distinct signal chemicals.

Then those cells assemble into a brain, apparently "randomly" with only crude, coarse patterns that are at best statistical in nature. Some cells are longer, some shorter, some with more interconnects, some with less, but no two perfectly alike.

Then, then, somehow... waves hands... magically this encodes that "wide hips are sexually attractive" in a way that turns up fully a decade later, well into the "pre-training" phase!!!

What... the... %#%@!

How does that work!? How does any of that work?

Y'all work in AI, ML, or adjacent to it. You know how hard it is to train a model to learn to detect anything even with thousands of examples!

PS: Human DNA contains only 750 MB (62 billion bits) of information, of which maybe 0.1% to 1% directly code for brain structure and the like. Let's be generous and say 10%. That is just 75 MB that somehow makes us scared of snakes and spiders, afraid of heights, attracted to the opposite sex, capable of speech, enjoy dancing, understand on instinct what is a "bad" or "good" smell, etc, etc...

For us it's hard to train a model because our compute and resources is nothing compared to nature's "compute" the whole universe: "it" has absurdly more resources to run different variations and massively parallel compute to run the evolutionary "algorithm", if you think about all the chemical building blocks, proteins, cells, that was "tried" and didn't survive.

From that angle our artificial models seem very sample efficient, but it's all hard to quantify it without know what was "tried" by the universe to reach the current state. But it's all weird to think about because there is no intent in natures optimizations it's just happens because it can and there is enough energy and parallel randomness to eventually happen.

And the real mystery is not how evolution achieved this but that the laws of chemistry/universe allow self-replicating structures to appear at all. In an universe with different rules it couldn't happen even with infinite trial and error compute.

The brain absolutely and biology in general when one starts digging.

Discovery of DNA was positioned as a "Biology: Mission Accomplished" - it's far from true. We don't understand all of DNA and epigenetics. We don't have a good understanding of how life began.

Back to the brain, it's power consumption to capabilities, weight to capabilities is just insane. The link to brain size and intelligence is a mystery as well - jumping spiders, octopus, corvids, parrots ...

There is still a big discussion of nature vs nurture. Did not follow the subject you mention but many things can be in fact just learned.

Also, as mentioned previously, there is more than the DNA at work - like at least epigenetics, but I guess the fetus is influenced a lot by the mother's body.