3 ms·

I think this is 'Reaction-diffusion models' https://en.wikipedia.org/wiki/Reaction%E2%80%93diffusion_system https://en.wikipedia.org/wiki/Reaction%E2%80%93diff

I think this is 'Reaction-diffusion models' https://en.wikipedia.org/wiki/Reaction%E2%80%93diffusion_system https://en.wikipedia.org/wiki/Reaction%E2%80%93diffusion_sys... The idea iiuc, is that pattern formation in animals depends on molecules diffusing through the growing system (the body) and reacting where the waves of molecules overlap.

Kim_Bruning 8mo ago
To me , the 1952 paper is very important, since it shows up in theoretical biology a lot. Seeing generality at all these different emergence levels is really exciting to me. (and it makes me sad when others don't see it). Can you imagine? Set up a few gradients, and now you have coordinates. Put all the bits where they're supposed to go like uhhh... GLSL sort of loosly fits. How cool is THAT? More recently I've gotten into all sorts of debates on HN by people who like Searle. Often the argument goes "Turing is all wrong, he knows nothing about biology." Turns out towards the end of his life he was applying his knowledge to biology. Most of which experimentally verified, besides! (ps. just to be sure: Never wondered how DNA encodes the trick? You started out as a clump of cells, all the same. How did one part decide to become the tip of your nose, and the other the tips of your toes? Segmentation controlled by Turing patterns all the way down!)
- amiga386 8mo ago
  > How did one part decide to become the tip of your nose, and the other the tips of your toes? Homeobox genes, right? https://en.wikipedia.org/wiki/Morphogenesis https://en.wikipedia.org/wiki/Morphogenesis Yes, https://en.wikipedia.org/wiki/The_Chemical_Basis_of_Morphogenesis https://en.wikipedia.org/wiki/The_Chemical_Basis_of_Morphoge... But also: https://en.wikipedia.org/wiki/Body_plan#Genetic_basis https://en.wikipedia.org/wiki/Body_plan#Genetic_basis https://en.wikipedia.org/wiki/Homeobox https://en.wikipedia.org/wiki/Homeobox https://en.wikipedia.org/wiki/Hox_gene https://en.wikipedia.org/wiki/Hox_gene https://en.wikipedia.org/wiki/Gene_regulatory_network https://en.wikipedia.org/wiki/Gene_regulatory_network https://en.wikipedia.org/wiki/Epigenetics https://en.wikipedia.org/wiki/Epigenetics https://en.wikipedia.org/wiki/Cell_potency https://en.wikipedia.org/wiki/Cell_potency https://en.wikipedia.org/wiki/Evo-devo https://en.wikipedia.org/wiki/Evo-devo https://www.youtube.com/watch?v=ydqReeTV_vk https://www.youtube.com/watch?v=ydqReeTV_vk

Kim_Bruning 8mo ago

To me , the 1952 paper is very important, since it shows up in theoretical biology a lot. Seeing generality at all these different emergence levels is really exciting to me. (and it makes me sad when others don't see it). Can you imagine? Set up a few gradients, and now you have coordinates. Put all the bits where they're supposed to go like uhhh... GLSL sort of loosly fits. How cool is THAT? More recently I've gotten into all sorts of debates on HN by people who like Searle. Often the argument goes "Turing is all wrong, he knows nothing about biology." Turns out towards the end of his life he was applying his knowledge to biology. Most of which experimentally verified, besides! (ps. just to be sure: Never wondered how DNA encodes the trick? You started out as a clump of cells, all the same. How did one part decide to become the tip of your nose, and the other the tips of your toes? Segmentation controlled by Turing patterns all the way down!)

amiga386 8mo ago
> How did one part decide to become the tip of your nose, and the other the tips of your toes? Homeobox genes, right? https://en.wikipedia.org/wiki/Morphogenesis https://en.wikipedia.org/wiki/Morphogenesis Yes, https://en.wikipedia.org/wiki/The_Chemical_Basis_of_Morphogenesis https://en.wikipedia.org/wiki/The_Chemical_Basis_of_Morphoge... But also: https://en.wikipedia.org/wiki/Body_plan#Genetic_basis https://en.wikipedia.org/wiki/Body_plan#Genetic_basis https://en.wikipedia.org/wiki/Homeobox https://en.wikipedia.org/wiki/Homeobox https://en.wikipedia.org/wiki/Hox_gene https://en.wikipedia.org/wiki/Hox_gene https://en.wikipedia.org/wiki/Gene_regulatory_network https://en.wikipedia.org/wiki/Gene_regulatory_network https://en.wikipedia.org/wiki/Epigenetics https://en.wikipedia.org/wiki/Epigenetics https://en.wikipedia.org/wiki/Cell_potency https://en.wikipedia.org/wiki/Cell_potency https://en.wikipedia.org/wiki/Evo-devo https://en.wikipedia.org/wiki/Evo-devo https://www.youtube.com/watch?v=ydqReeTV_vk https://www.youtube.com/watch?v=ydqReeTV_vk