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SPIDER FAMILIES. "Most of the current diversity of spiders results from 2 major radiations −RTA clade (>21,000 spp.) and Orbiculariae (>11,000 spp.). The putative sister group of Orbiculariae in our hypothesis, the RTA clade, is even more diverse (>21,000). Hence, we cannot, by sister group comparison alone, claim that the invention of the orb web per se dramatically affected diversification rates. Notably, the most diverse families of spiders within the RTA clade are largely, or entirely webless, and have secondarily lost cribellate silk." http://www.pnas.org/content/106/13/5229.full View in LinkedIn

GENES IN CONTEXT OF CELLS. "It is meaningful, or biologically functional, only within the context of the cell, where a suite of molecular hardware collaborate in decoding and executing the encoded instruction (e.g. to make a protein). As such, biological information is an abstract global systemic entity, carrying meaning only within the context of an entire living system." https://lnkd.in/dTS7dFy View in LinkedIn

MEANING IN CONTEXT. "Biological information is distinctive in its contextual or semantic nature, in other words it means something. For example, a gene is just a random sequence of nucleotides when taken in isolation, and is indistinguishable from junk, or noncoding, DNA." 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

STRESSES ON AERIAL WEBS. "As spiders began to build aerial orb-webs, their silks faced new selective pressures. For example, insects in mid-flight strike webs with greater kinetic energy than experienced by ancestral substrate-bound webs (and derived sheet- and cobwebs) that intercept ambulatory prey, or prey attempting to land. Additionally, webs suspended in space are subjected to much greater wind stress, even more so if anchored to flexible substrates such as grasses." https://lnkd.in/dqTjK77 View in LinkedIn

AERIAL WEB EVOLUTION. "The Orbiculariae, so named for the classic orb-web they build, account for more than 25 per cent of spider diversity (11 880 + species). The evolution of the orb-web meant that spiders could build aerial webs suspended in space, freeing them from the limitations in web shape imposed by the substrate. The move to building aerial webs may represent the beginnings of an evolutionary arms race with flying insects that co-radiated alongside the spiders." https://lnkd.in/dHWBg9g View in LinkedIn

DIVERSITY AT ALL SCALES. "Some nanoscale structures within dragline silk (e.g. β-sheet crystals, β-turns) are found in most spider species. However, variation in biomechanical function can arise owing to diversity in silks at all structural scales." https://lnkd.in/dHWBg9g View in LinkedIn

SILK ELASTICITY BIOCHEMISTRY. "In addition to its strength, dragline silk is highly elastic when compared with synthetic fibres. Elasticity of dragline silk is determined largely by the semi-amorphous regions interconnecting the β-sheet crystals. These regions include helix-like structures and β-turns that are rich in glycine. When a silk fibre is subjected to tensile loading, the semi-amorphous regions unravel first owing to breaking of hydrogen bonds, which accounts for the high level of extensibility observed in silk." https://lnkd.in/dHWBg9g View in LinkedIn