
Ancient Turing Pattern Builds Feathers, Hair and Now Shark Skin - occamschainsaw
https://www.quantamagazine.org/ancient-turing-pattern-builds-feathers-hair-and-now-shark-skin-20190102/
======
70jS8h5L
Turing's papers on the subject formed part of the research for my dissertation
project, which culminated in a Matlab simulation of the skin patterns he
described with inhibitors/activators.

I recently converted it to JS and also Ruby, as an excuse for a few coding
exercises. It's still a work in progress, but can be found here:

[https://github.com/rai-hi/rails-skin-patterning](https://github.com/rai-
hi/rails-skin-patterning)

Demo here:

[https://skin-simulator.herokuapp.com/](https://skin-simulator.herokuapp.com/)

~~~
imglorp
Since you're in the field, maybe I could ask about your impression of
Wolfram's NKS? As a layperson, I understand it's a generalization of many
classes of such patterns.

[https://www.wolframscience.com](https://www.wolframscience.com)

~~~
70jS8h5L
Actually, the dissertation project was my only experience with the field.
Although I read some of NKS at the time, it's a distant memory and so I
wouldn't be able to say!

------
Angostura
In the late 90s I chatted with Brian Goodwin who was about to write this book
How the Leopard Changed Its Spots
[https://press.princeton.edu/titles/7043.html](https://press.princeton.edu/titles/7043.html)

Really interesting guy and the book covers a whole host of areas where self-
organising systems shape organisms without necessarily much genetic
intervention

------
AllegedAlec
Cool. It's fun to see how Turing patterns are everywhere in biology. However,
as Turing himself said (allegedly): 'Well the stripes are easy, but what about
the horse part?'

~~~
anigbrowl
Having developed an amateur interest in cell biology over the last few years,
the single most interesting thing I've learned is that Interglobulin-M cells
cells just happen to have same basic morphology as the kind of animals that
they come from.

~~~
ColanR
I have no idea what that means, but I'm curious to know. Can you point to
anything I could read?

~~~
anigbrowl
I'm so sorry, I should have written immunoglobulin-M and didn't notice my
mistake. I don't feel qualified to recommend a text, I just follow references
from here.

[https://en.wikipedia.org/wiki/Immunoglobulin_M](https://en.wikipedia.org/wiki/Immunoglobulin_M)

~~~
ColanR
Thanks. :) That's what I found when I searched, but the spelling difference
threw me off.

------
anigbrowl
I feel like this pattern is a great example of how mathematicians, scientists,
and technologists should focus their attentions on things that are economical
and 'good enough' rather than fetishizishing ever-increasing levels of
precision.

While, say, calculating fundamental constants to the _n_ th degree of
precision is fun and intellectually satisfying in many respect, the marginal
utility of each additional digit of precision asymptotically approaches zero
so it's really a self-indulgent luxury. But this fetishizing of precision also
has drawbacks; it misdirects resources and effort into improvements whose
benefits fall far short of the costs.

You wouldn't use a laser pointer to explore a room. Of course you _could_ ;
but mapping a topological space using LIDAR is only possible because we have
computers to do the vast amount of number crunching required, and it's only
very recently that we've gone from very sparse representations to ones of
sufficiently high resolution to give us representations that are immediately
recognizable as familiar spaces.

I will take fast proximity over slow exactitude any day of the week; I want
models that get me close enough with very few parameters rather than more
perfect ones that require a thick book's worth of specifications to
articulate.

------
crawfordcomeaux
This story makes me wonder when we're going to change the culture of science
so as to minimize the time it takes for something to be taken seriously.

~~~
ColanR
Unfortunately, this is more a generalized problem of human disbelief in the
unlikely than anything specific to science. We can't really say, 'scientists
now have to be more receptive to weird ideas'.

------
dr_dshiv
And, maybe, explaining the geometrical hallucinations from psychedelics and
10hz flicker: [https://www.quantamagazine.org/a-math-theory-for-why-
people-...](https://www.quantamagazine.org/a-math-theory-for-why-people-
hallucinate-20180730/)

------
parentheses
This pattern of inhibitor/activator is one that can be used in social sciences
as well.

This also fits well with how codebases are managed: linting, style, patterns,
etc.

------
swamp40
The picture of the model vs real shark denticles isn't very compelling to me.
Maybe they just chose a poor example?

------
ptah
can this be used in generating textures for 3d models

~~~
lalos
It's one way of doing it, yes. See this project that does it
[https://github.com/gollygang/ready](https://github.com/gollygang/ready)

