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SHELL SPACETIME. “Time represents the pigmentation pattern that was laid down in previous bouts, whereas space is the dimension along the growing edge of the cell. The resulting filtered activity is passed through nonlinearities for excitation and inhibition, and this net activity drives the secretory cells that lay down the new pigmented shell material.” https://lnkd.in/dwfZQzE View in LinkedIn

PATTERN GENERATION. “Fig 1. (C) Simple pattern on a Conus shell and how the model extrapolates the previous pattern to produce the current day's pigment secretion. The pigmentation pattern is read by the sensory cells in the mantle. This activity is then passed through the space–time filter of neural activation and inhibition.” https://lnkd.in/dwfZQzE View in LinkedIn

TASTING PATTERNS. “Fig 1. (B) Cross-section of the mantle showing how the sensory cells “taste” the previously laid pigment patterns that are processed by the central ganglion and sent to the mantle network that controls the pigment-secreting cells.” https://lnkd.in/dwfZQzE View in LinkedIn

GANGLIONIC RING. “Fig. 1. The neural-network model of the mantle. (A) Rough anatomy of a generic shelled mollusk. Note the “brain,” where the neural patterns are processed consists of a ring of ganglia.” https://lnkd.in/dwfZQzE View in LinkedIn

CONE SHELL PHYLOGENIES. “The species have a well supported phylogeny that allows us to infer rates and patterns of parameter evolution.” https://lnkd.in/dwfZQzE View in LinkedIn

Cooking time, that alchemy that transforms great materials into food. View in LinkedIn

SO ENDS this first of two weekends focused on patterning in the cone shell family. Fortunately, there are so outstanding virtual collections of cone shells, making actual collections by enthusiasts a thing of the past. These are an enormous source of pattern configurations, beautifully curated, for the mathematician or biologist to study without plundering the reefs. https://lnkd.in/d8vCADd View in LinkedIn

MORPHOGEN MODELS. “Therefore, in principle, morphogen models could have been used instead of the neural model. From a practical viewpoint, however, this would be considerably more difficult because a separate morphogen model is required for each shell pattern, whereas the neural model has a single set of parameters that are varied to match each pattern.” https://lnkd.in/dwfZQzE View in LinkedIn

THE COMPROMISE. “From a theoretical viewpoint, morphogen models can be viewed as an approximation to the neural net model when the range of communication between neurons is short.” https://lnkd.in/dwfZQzE View in LinkedIn

NATURE OF PATTERNING. “Structural studies provide strong evidence that shell patterns are a neurosecretory phenomenon rather than a diffusing morphogen phenomenon.” https://lnkd.in/dwfZQzE View in LinkedIn