system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why is the golden ratio common to so many things of different nature?
gpt
Say you have a seed. Deep down in the genetic code of the seed is the simple genetic code that says "have these cells build more of themselves." If you let all those cells grow, the ratio between old cells and new cells will usually be the golden ratio.

The golden ratio is so common in nature because it is the product of such a simple idea: the ratio between the first thing and the second thing is the same as the ratio between both those things and a third thing. It's what you always get when you tell cells or leaves or branches or scales to just "grow more of yourself."