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HARD TO ANSWER. "Plenty of protists are capable of phenotypic differentiation but have never made the transition to true multicellularity, although they may exhibit highly collective and coordinated behaviors." https://lnkd.in/dTS7dFy View in LinkedIn

ORB WEB GEOMETRY. "Our analysis shows that orb webs arose a single time. The orb appears to be derived from a substrate-bound web, likely an irregular ground web or brushed sheet web. The evolution of orb webs was marked by a dramatic increase in geometric regularity, resulting from increased behavioral stereotypy of spinning." http://www.pnas.org/content/106/13/5229.full View in LinkedIn

DIVERSIFIED BY SILK. "In contrast to megadiverse orders of insects, evolutionary diversification of spiders is not coupled with major trophic shifts. Spider diversification is instead linked to key innovations in silk use." http://www.pnas.org/content/106/13/5229.full View in LinkedIn

SILK INNOVATIONS. "The evolutionary diversification of spiders is attributed to spectacular innovations in silk. Spiders are unique in synthesizing many different kinds of silk, and using silk for a variety of ecological functions throughout their lives, particularly to make prey-catching webs." http://www.pnas.org/content/106/13/5229.full View in LinkedIn

SPIDER BEHAVIORAL SHIFTS. "Accompanying cribellum loss in both groups is a release from substrate-constrained webs, whether by aerially suspended webs, or by abandoning webs altogether. These behavioral shifts in silk and web production by spiders thus likely played a key role in the dramatic evolutionary success and ecological dominance of spiders as predators of insects." https://lnkd.in/db9PJGx View in LinkedIn

REPEATED EVOLUTIONARY LOSSES. "Within the “RTA clade,” which is the sister group to orb-weaving spiders and contains half of all spider diversity, >90% of species richness is associated with repeated loss of cribellate silk and abandonment of prey capture webs." http://www.pnas.org/content/106/13/5229.full View in LinkedIn

THUMBNAIL OVERVIEW. "Spiders first began spinning silk approximately 400 Ma. There are at least 41 000 described species of spiders spinning silk in every known terrestrial ecosystem except Antarctica. Many of these spiders produce seven to eight distinct types of silks that are used in a variety of webs, ranging from silk-lined burrows in the ground to aerial orb-webs to the seemingly chaotic three-dimensional cobwebs." https://lnkd.in/dHWBg9g View in LinkedIn

DIVERSE TOOLKIT. "Our study quantifies the mechanical and material properties of the fibrous silks spun by Argiope argentata. As a whole, the silks possess extraordinary properties, but are also strikingly diverse. These silks provide orb-weaving spiders with diverse toolkits of fibers that seem fine-tuned for particular ecological functions. This variety is reflected in not just the distinctive mechanical properties of each silk, but also in the underlying molecular structures and amino acid sequences of the fibroins." https://lnkd.in/dHR5T8n View in LinkedIn

SILK PROPERTIES. "In addition to high levels of structural diversity among webs, the biomechanical properties of silks are also highly variable. This variation may be due to a range of physiological and abiotic mechanisms, such as the rate of spinning, pH levels in the silk glands, humidity and temperature. Diet may also influence availability of silk proteins, which will in turn affect silk properties." https://lnkd.in/dHWBg9g View in LinkedIn

REVERSAL OF INFORMATION FLOW. "Higher levels of organization into a biological system should be characterized by a transition from bottom-up to top-down causation, mediated by a reversal in the dominant direction of information flow." https://lnkd.in/dTS7dFy View in LinkedIn