How does a baby bird know to act like a poisonous worm when a predator shows up? The answer is genetic memory, but how does it work? How does it get encoded into dna, passed down, and executed.
In: Biology
It might help to look at what our own instincts “feel” like. For example, how do you know to eat food and not to eat mud? It’s probably a universal thing for people to try eating dirt, mud, etc. as a child, but outside of a few cases, this is something you do not make a habit of. Things like the flavour tell us mud is bad. Why is it bad? Because it tastes bad. Why is food good? Because it tastes good (at least most of it, some can be hit or miss).
But flavour isn’t an inherent quality of materials. It’s purely in our minds, caused by taste receptors on our tongue reacting to certain molecules. The tastes considered “good” are tied to the presence of certain molecules, and vice versa for bad. The end result is that we “know” to eat food without specifically having to be taught.
This connects to genes because the instructions for how to make taste receptors are encoded in DNA. Variations in the exact shape result in different preferences, such as the same food tasting pretty good to one person, but terribly bitter to another.
>How does it get encoded into dna, passed down, and executed.
You’re thinking of it backwards. Things didn’t start “outside” the DNA and then get encoded into it. Things start as DNA and then the DNA makes us, who do things.
As for how DNA is passed down and used, there’s a wide variety of educational videos and articles meant to teach this topic. [Crash Course youtube series](https://www.youtube.com/watch?v=CBezq1fFUEA&list=PL3EED4C1D684D3ADF&index=11) and [Khan Academy article](https://www.khanacademy.org/science/ap-biology/gene-expression-and-regulation/transcription-and-rna-processing/a/overview-of-transcription). If you have further questions, do not hesitate to ask!
Latest Answers