How does DNA translate to an animal’s natural instincts? As in, how can genetic code give an animal innate knowledge about the natural world while the animal is developing in the lightless womb of its mother?

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How does DNA translate to an animal’s natural instincts? As in, how can genetic code give an animal innate knowledge about the natural world while the animal is developing in the lightless womb of its mother?

In: Biology

Let’s look at a very very simple example – ticks.

Ticks have a few instincts – “Move towards warmth” “Move towards the scent of carbon dioxide” and “When the smell of carbon dioxide is very strong – BITE.”

These are not learned behavior; a tick starts exhibiting these as soon as it hatches from an egg. Moving towards warmth means that rather than lying on the ground, where they’re unlikely to be picked up by an animal, they crawl to the top of grass, where the warmth of the sun is greater – and where they’re more likely to get picked up by an animal.

Once they’re on an animal, they start to burrow towards the source of carbon dioxide – the mammal’s skin, which is constantly emitting carbon dioxide. There, the scent is very strong, and the tick bites and starts to feed.

These are all hard-wired into the tick’s brain. The “warmth sensing” brain circuitry feeds directly into the “movement” brain circuitry.

These are simple examples, but the kind of provide a template for more complex examples. Mammals have a hard-wired desire to stay close to their mother when very young, to seek out and suck on nipples, to flee from loud sounds.

It’s not really knowledge that the genetic code is teaching the animal, they’re reactions hardwired into the “design” to the body.

For example, if you accidentally touch something very hot you’ll pull back from it. You didn’t think about this, it happened faster than you could think about it. It’s a reaction built into the hardware of your body: if massive unexpected pain, move away, don’t bother asking the brain what it thinks, it’s too slow.

DNA is a very complex storage mechanism. A far more advance than our current knowledge of ‘storing’ anything.

Take an example of humans. We do not meed to teach a kid to run away from a snake when he sees it even if he has never seen anything like that before. It is written – hard wired within their brains. Our kids automatically hates bitter taste and loves sweet items. We don’t need to teach them this because it was written in our genes slowly and gradually in evolution.

It is like a mathematical formula. You apply it with some inputs and it will directly provide an output without actually deducting the formula again and again. Hard wiring a brain to react in certain activities is exactly the same.

You want to save something for a minute? Use your brain. For a day? Use paper. For a month? Use metal or rocks. For a year? Use electronics. But for as long as you live? Use DNA.

All knowledge comes from the structure of neurons, and all neurons grow as the result of a process. All processes create particular structures based on chemical cues.

Think of this as a “default configuration”.

So if the default configuration just so happens to encode a knowledge or behavior that is useful, that is what we call an “instinct”.

When DNA defines a process that makes default shapes that have survival value, as a result of mutation, the mutant survives more, and passes on the DNA that creates that structure by default.

The problem in understanding is just that it’s hard making the connection that *all your memories and behaviors are really just structures*, and if you had a structure in your brain for, say, a vacation on Mars, you would remember a vacation on Mars.

DNA is code that leads to a product. Those products are then used to build circuits. The circuits range from simple to complex; they could be single molecules or reactions to the animal’s environment.