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COMPLEXITY OF SHELLS, and their construction from within. A truly beautiful deck worth reading. https://lnkd.in/dPSBurq View in LinkedIn

"THE EVOLUTION OF A SHELL. In the second process, the aperture shape evolves, producing ornamentation such as ribs or spines on the shell surface." https://lnkd.in/dSJZzWB View in LinkedIn

"THE EVOLUTION OF A SHELL. In one process, the shell aperture undergoes coiling, dilation, translation, and rotation. these rates are highly controlled throughout the shell development, and the resulting shell form has the mathematical regularity." https://lnkd.in/dSJZzWB View in LinkedIn

"LOGARITHMIC COILING IN SHELLS was first mathematically described over a century ago, the developmental bases of these shell forms remains unknown. Similarly, the three-dimensional ornamentations on shells, which can be seen as a deviation from simple coiling, emerge through largely unknown processes." https://lnkd.in/dSJZzWB View in LinkedIn

COILING GENES. "The direction of snail shell coiling is controlled by a single pair of genes ... there is a right-coiling allele D, which is dominant to the left-coiling allele d ... However, the direction of cleavage is determined not by the genotype of the developing snail, but by the genotype of the snail's mother." https://lnkd.in/dctHRnB View in LinkedIn

COILING FIXED. "Usually, the direction of coiling is the same for all members of a given species. Occasionally, though, mutants are found." https://lnkd.in/dctHRnB View in LinkedIn

HANDEDNESS. "Most shells are right handed and possess overlapping whorls that coil around a single axis. Spiral coiling also appears to be dictated by a set of ‘behavioural’ rules involving shell sculpture ... Opisthostoma shells are 'sinistroid’ due to a reversal in coiling direction in the last half-whorl ... can possess two or three different coiling axes." https://lnkd.in/dNeQF-g View in LinkedIn

"THE SOLUBLE COMPONENT of the shell matrix acts to inhibit crystallization when in its soluble form, but when it attaches to an insoluble substrate, it permits the nucleation of crystals. By switching from a dissolved to an attached form and back again, the proteins can produce 'bursts' of growth, producing the brick-wall structure of the shell." https://lnkd.in/dtpKQHE View in LinkedIn

THE INSOLUBLE PROTEINS. "Hundreds of soluble and insoluble proteins, control shell formation. Insoluble proteins tend to be thought of as playing a more important/major role in crystallization control ... The nacreous layer has an organic framework of the protein MSI60, which has a structure a little like spider silk and forms sheets." https://lnkd.in/dtpKQHE View in LinkedIn

"THE ORGANIC MATRIX forms the scaffold that directs crystallization, and the deposition and rate of crystals is also controlled by hormones produced by the mollusc. The formation of the shell involves a number of genes and transcription factors." https://lnkd.in/dtpKQHE View in LinkedIn