neural control of cell formation in molluscs

monty

Colossal Squid
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#1
Very interesting stuff:

http://www.sciencedaily.com/releases/2009/04/090402092714.htm

preprint of paper here (I can't find the official one yet):

http://www.cnr.berkeley.edu/~goster/pdfs/Shells.pdf

The short version is that the shape and pigmentation of gastropod shells have been found to be (at least in simulation) controlled by a neural network with a small number of parameters. The preprint also has a brief section on applying the same results to cuttlefish patterns.

It looks like they didn't study the shape of nautilus septa (or I just missed it on my first skim) but it would be fascinating to see if their simulation can get the complex suture patterns in ammonites! After all, for a computer simulation, you don't need the living animal!
 

monty

Colossal Squid
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#2
Another reference, with some movies showing the shell growth and pattern formation:

http://www.berkeley.edu/news/media/releases/2009/04/01_seashells.shtml

Also, my half-baked thoughts on ammonite sutures are now more progressed, since I read the paper pre-print:

the model presented in the paper discusses how growth rate vectors can be controlled by the same system (neurally implemented Local Activation with Lateral Inhibition LALI) as the pigmentation. This is described for the outer shell shape, which can include at least some ornamentation and whatnot, but if applied to the septa of ammonites, I believe that if the septum were started from the smooth center, it could easily explain how the complex-yet-regular pattern of ripples leads to the sutures where the septa meet the shell walls. Unfortunately, the version of the paper I have simply says "we will deal with this in detail in a subsequent publication" so I can't really get the exact information, but it only now occurred to me that the ripples at the edges of a giant clam are analogous to, and possibly created by the same mechanism as, the septa in complex-sutured ammonites.

p.s. does anyone have access to the full text of this:

http://www3.interscience.wiley.com/journal/119919281/abstract
 

monty

Colossal Squid
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#4
Architeuthoceras;135587 said:
We need a little emoticon showing something going way over that smilies head, just so I could use it here. :confused:

Sorry Monty, no access to Lethaia Here.:sad:
Any particular questions I can try to answer? I thought the Berkeley page about it with the movies did fairly well at explaining...
 

Architeuthoceras

Architeuthis
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Moderator
#6
monty;135588 said:
Any particular questions I can try to answer? I thought the Berkeley page about it with the movies did fairly well at explaining...
Nothing particular Monty, just not used to all the nomenclature used for extant stuff. :wink:

dwhatley;135591 said:
Something like this?
Those will work :smile:
 

DWhatley

Cthulhu
Staff member
Moderator
#7
The attempted fossil look good in the larger image but didn't shrink as well as I hoped :hmm: Give me an A for effort though.
 

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