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SO ENDS this first of two weekends looking at the evolution of complexity in a granular way; the molecular manifestations and mechanisms that give rise to complexity follow familiar themes, in particular the repurposing of old parts, and the need for cooperation between parts to create novelty, in often ingenious combinations. Biochemistry is full of such ingenuity, which then becomes manifest phenotypically. View in LinkedIn

MODEL #3 CO-OPTION. "Many complex biological systems are characterized by a tight integration of component parts. New associations of existing substructures or proteins may give rise to new functions, thus it is not necessary for the system to evolve in toto." https://lnkd.in/dJG4bYH View in LinkedIn

MODEL #3 CO-OPTION. "Genes co-opted for new functions can give rise to developmental and physiological novelties." https://lnkd.in/dJG4bYH View in LinkedIn

MODEL #3 CO-OPTION. "In fact, a common theme of biological evolution is that existing structures are often put to new uses, and new structures are created from the old. “Co-option” is the term used to describe the recruitment of existing structures for new tasks. This recruitment can explain evolutionary increases in biological complexity." https://lnkd.in/dJG4bYH View in LinkedIn

MODEL #3. Co-option model. "Natural selection acts upon an existing set of structures within a particular environmental context. An altered environment demands altered responses from an organism. Consequently, it should not be surprising to find in the fossil record and in comparative anatomical and physiological studies evidence that some structures have been modified through time to serve different functions." https://lnkd.in/dJG4bYH View in LinkedIn

MODEL #2 NARRATIVE. "Carbon atoms entering the Calvin-Benson cycle within a chloroplast may find their way into any one of many different molecules and be shunted into other pathways. There are also many cases of a redundancy of enzymatic components, or variant isoforms. Gene duplications increase the number of genes in a species, which can then evolve in different ways." https://lnkd.in/dJG4bYH View in LinkedIn

MODEL #2 NARRATIVE. "Metabolic systems can be viewed as complex traits, because individual metabolic enzymes in isolation are rarely pertinent to in vivo physiology until they become part of an organized metabolic pathway. Extant metabolic pathways in general contain a set of enzymes catalyzing sequential reactions in a highly concerted manner." http://onlinelibrary.wiley.com/doi/10.1111/nph.12416/full View in LinkedIn

MODEL #2 NARRATIVE. "Many biochemical systems are characterized by “redundant complexity”. Biochemical pathways rarely function in isolation; rather, one pathway interconnects with another." https://lnkd.in/dJG4bYH View in LinkedIn

MODEL #2. "Scaffolding is another mechanism whereby irreducible complexity might be established. In the incremental additions model, a beneficial association of components becomes an essential association because mutational events compromise the independent activity of one or more component parts. In the scaffolding model, superfluous components are lost, leaving a system in which the remaining components appear tightly matched as if they were specifically designed to fit and function together." https://lnkd.in/dJG4bYH View in LinkedIn

AUTONOMOUS CREATIVITY. "No pictures are programmed in advance; AARON isn’t just a modern-day version of an eighteenth-century drawing automaton, repeatedly churning out the same picture. Instead, AARON makes an endless supply of wholly original artwork. AARON now produces its original paintings without Cohen’s intervention." https://lnkd.in/d4iuTqi View in LinkedIn