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Natural genetic engineering (NGE) is a class of process proposed by molecular biologist James Shapiro to account for novelty created in the course of biological evolution. Shapiro developed this work in several peer-reviewed publications and later in his book ''Evolution: A View from the 21st Century''. He uses NGE to account for several proposed counterexamples to the central dogma of molecular biology (the subsequently partly rejected proposal of 1970 that the direction of the flow of sequence information is only from DNA to DNA or DNA to RNA to proteins, and never the reverse). Shapiro drew from work as diverse as the adaptivity of the mammalian immune system, ciliate macronuclei and epigenetics. The work gained some measure of notoriety after being championed by proponents of Intelligent Design, despite Shapiro's explicit repudiation of that movement. ==Concept== Shapiro first laid out his ideas of natural genetic engineering in 1992〔 and has continued to develop them in both the primary scientific literature〔〔〔〔 and in work directed to wider audiences,〔〔 culminating in the 2011 publication of ''Evolution: A View from the 21st Century''.〔 Natural genetic engineering is a reaction against the modern synthesis and the central dogma of molecular biology. The modern synthesis was formulated before the elucidation of the double-helix structure of DNA and the establishment of molecular biology in its current status of prominence. Given what was known at the time a simple, powerful model of genetic change through undirected mutation (loosely described as "random") and natural selection, was seen as sufficient to explain evolution as observed in nature. With the discovery of the nature and roles of nucleic acids in genetics, this model prompted Francis Crick's so-called Central Dogma of Molecular Biology: "() information cannot be transferred back from protein to either protein or nucleic acid."〔Crick, F.H.C. (1958): (On Protein Synthesis. ) Symp. Soc. Exp. Biol. XII, 139-163. (pdf, early draft of original article)〕 Shapiro points out that multiple cellular systems can affect DNA in response to specific environmental stimuli. These "directed" changes stand in contrast to both the undirected mutations in the modern synthesis and (in Shapiro's interpretation) the ban on information flowing from the environment into the genome. In the 1992 Genetica paper that introduced the concept, Shapiro begins by listing three lessons from molecular genetics: * there is a surprising amount of genetic conservation across taxonomic boundaries, * the mosaic structure of the genome results in multiple nonlocal genes having multiple phylogenic effects, and, drawing on the work of his friend and collaborator Barbara McClintock, * the existence of multiple cellular mechanisms (including mobile genetic elements) that can restructure DNA. From these, Shapiro concludes:
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