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FRAGMENT FROM NATURE focuses on the biology of spider silk for two weekends followed by a section on the geometry of spider webs. It is not enough that these insects make the toughest material in the planet, but that they also engage in complex geometrical shapes as well. Reminiscent of MC Escher's obsession with tressellations and Kepler's six-fold geometry of snowflakes, the subject of the last two postings. View in LinkedIn

COUPLED STATES. "The coupling of states to dynamics is perhaps most evident for the case of the genome, in which the expressed set of instructions – i.e. the relative level of gene expression – depends on the state of the system - i.e. the composition of the proteome, environmental factors, etc. - that regulate the switching on and off of individual genes." https://lnkd.in/dTS7dFy View in LinkedIn

NEW APPROACH. "This is in marked contrast to the traditional approach to dynamics, where the physical states evolve with time but the dynamical laws remain fixed, or change over much longer time scales." https://lnkd.in/dTS7dFy View in LinkedIn

SECOND EVOLUTION. "The second major shift involves the mechanism of adhesion, from dry cribellate fibrils that adhere through van der Waals forces and hygroscopic interactions to chemically adhesive viscid glue in ecribellate spiders. This results in webs with greater adhesion per surface area and may have facilitated the transition from horizontal to vertical web orientation in modern orb spiders, which is associated with increased prey interception rates." http://www.pnas.org/content/106/13/5229.full View in LinkedIn

SLIPPERY IDEA. "Biological information is a notoriously difficult concept to define. This difficultly stems in part from the fact that in living systems the dynamics are coupled to the information content of biological states such that the dynamics of the system change with the states and vice versa." https://lnkd.in/dTS7dFy View in LinkedIn

FIRST EVOLUTION. "Instead of cribellate and ecribellate orb webs evolving in parallel, orb monophyly explicitly implies that dry cribellate capture spirals were replaced by ecribellate gluey spirals. This involves 2 major changes. First, a shift in the silk used to produce the core fibers of capture threads, resulting in novel tensile properties." http://www.pnas.org/content/106/13/5229.full View in LinkedIn

TRANSITIONS DRIVEN BY INFORMATION. "We propose that these major transitions, corresponding to major jumps in biological complexity, are associated with information gaining causal efficacy over higher levels of organization." https://lnkd.in/dTS7dFy View in LinkedIn

UNIQUE CONSEQUENCE OF INFORMATION. "The result is that the update rules change with time in a manner which is both a function of the current state and the history of the organism. This feature of “dynamical laws changing with states”, as far as we know, seems to be unique to biological organization and is a direct result of the peculiar nature of biological information." https://lnkd.in/dTS7dFy View in LinkedIn

THE ONLY SPECIES where the individual has the power to change ecosystems are humans. In nature, species are the agents of change, not individuals. But because of the structure of human societies, power is concentrated in a few individuals, whose decisions can have sweeping impacts on large numbers of issues. Problematic evolution. View in LinkedIn

SO ENDS this part of the contemplation of the biology of the spider web. The lasting poignancy of early morning walks in English dew or frost to see spider webs in the grass and bushes outlined like pear necklaces, or to see them on a Spanish veranda railing surviving high winds, is embedded in my mind forever. Each an image seared. View in LinkedIn