How much data does DNA have for things like skin and fur colors, especially in the case of weight gain?

Question

Sorry if this doesn’t make sense or is dumb

So to my understanding, your dna contains all of the code for how your phenotypes are expressed, including in your skin of course. Like where moles/birthmarks go, and for animals, how different fur colors manifest. Pigment and stuff is programmed to go to specific areas and things like that

But how much data is there? Because if someone gains a lot of weight, they also gain a lot of new skin. Does your dna just have an endless pattern for what features your skin will have? Or when an animal is really overweight, how does the dna just keep on generating a fur pattern indefinitely? I can understand when it comes to skin how maybe moles and things are a separate manifestation, but to my knowledge fur color is very tied to pigment sources placed in a pattern. It’s not random, because the colors are never just scattered without reason. But how does it decide in what manner to continue the pattern? Of course DNA is a finite thing, so does it eventually just loop back around? A repeating pattern, reusing data?

Sorry if I’m totally misunderstanding how this works lol

In: Biology

Answer 1

I am not sure of the right answer, but I think I can explain a flaw in your thinking. DNA is not a blueprint of your body. DNA is more like a set of instructions to build the things that build your body.

Consider the examples: A city blueprint would be a map with all the roads and building and stores already laid out. If the city needed to grow the builders would just consult the map. This would be DNA as a blueprint.

Now imagine a city with rules like 1. Don’t put sewage next to schools. 2. Buildings should be at least 3 stories tall. 3. If people are hungry build a grocery store. If the city needed to expand, the builders would just follow the rules. This would be DNA as instructions.