• Rather, development is the process whereby this information comes to exist.12 The recipe is written during development, not prior to development.
Richard C. Francis., Epigenetics : the ultimate mystery of inheritance, 2011
p.126
These recipe/program metaphors are attractive because they connect the basic intuitions common to all versions of preformationism to human artifacts with which we are all familiar, from cakes to graduation ceremonies.11 Whatever their intuitive appeal, these metaphors cannot withstand even the most cursory scrutiny. You couldn't cook up a single cell, much less a human being, given the instructions in the genetic recipe. Much of what you need to know lies elsewhere.
p.126
More to the epigenesist point, most of the information in the recipe that goes into making you is not there from the outset. Rather, development is the process whereby this information comes to exist.12 The recipe is written during development, not prior to development.
(Epigenetics : the ultimate mystery of inheritance / Richard C. Francis. ── 1st ed., 1. genetic regulation., 2. epigenesis., 3. adaptation (biology), QH450.F73 2011, 572.8'65──dc22, 2011, )
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• the ... hypothesis did not apply to moments of crisis., p.106, Sebastian Mallaby., More money than god : hedge funds and the making of a new elite, 2010.
• [models] do not work in crisis; rather, the models stop working.
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George P. Richardson, Feedback thought in social science and systems theory, 1991 [ ]
p.202
Biologists have been puzzled by the fact that the amount of information stored in the genes is much smaller than the amount of information needed to describe the structure of the adult individual. The puzzle is now solved by noticing that it is not necessary for the genes to carry all the information regarding the adult structure, but it suffices for the genes to carry a set of rules to generate the information (Magoroh Maruyama, p.308)
Maruyama, Magoroth (1963). The Second Cybernetics: Deviation-Amplifying Mutual Causal Processes. American Scientist 51: 164-179. Reprinted in Buckley (1968), pp. 304-316.
-- (1974). Paradigms and Communication. Technological Forecasting and Social Change 6: 3-32.
(Richardson, George P., Feedback thought in social science and systems theory, copyright © 1991 by the University of Pennsylvania Press)
(Feedback thought in social science and systems theory / George P. Richardson (1991), 1. social science--methodology., 2. feedback control systems., p.202)
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• Secondly, it is in most cases impossible to discover the simple generating rules after the pattern has been completed, except by trying all possible sets of rules.
• When the rules are unknown, the amount of information needed to discover the rules is much greater than the amount of information needed to describe the rules.
• In this sense, the information required to describe the adult individual was not contained in the initial tissues but was generated by their [cell tissues] interactions during the growth process.
POSITIVE FEEDBACK : a general systems approach to positive/negative feedback and mutual causality, edited by John H. Milsum, 1968
pp.90-92
... The amount of information needed to describe the resulting pattern is much more than the amount of information needed to describe the generating rules and the positions of the initial tissues, because the pattern is generated by rules and by the interaction between the tissues. In this sense, the information required to describe the adult individual was not contained in the initial tissues but was generated by their interactions during the growth process.
Besides generating information, this type of process has two additional interesting features. First, it is strictly deterministic, and therefore when the locations of the initial tissues are identical into two embryos, the resulting adults will be exactly identical, no matter how complex. Secondly, it is in most cases impossible to discover the simple generating rules after the pattern has been completed, except by trying all possible sets of rules. When the rules are unknown, the amount of information needed to discover the rules is much greater than the amount of information needed to describe the rules. This means that there is much more waste, in terms of the amount of information, in tracing the process backwards than in tracing it forward. A geneticist would waste much time and energy by trying to infer the characteristics of the embryo from the characteristics of the adult organism. It would be more profitable to perform experiments in embryonic interference and embryonic grafting. The same is true also for the study of other deviation-amplifying mutual causal processes such as history of mental illness.
Since information is generated by the interaction between various parts of the embryo, it is not necessary for each part of the embryo to contain information regarding the body part it is destined to become. It partly receives the information from other parts of the embryo and from its relationships to them. For example, in embryo of certain species, if the part which would become an eye is transplanted at an appropriate stage of the embryonic development into the part which would become skin, the eye-tissue becomes skin. It receives information for its growth from its surroundings.
We have discussed mainly the structure-generating aspect of the interaction between the parts of the embryo. But the interaction has also a structure-stabilizing aspect. Let us look at the example of the grafted eye tissues again. When they were grafted on skin tissues, the skin tissues made the would-be-eye tissues into skin tissues counteracting against the possibility that the would-be-eye tissues might become an eye.
Though it it not yet clear what the pattern-generating interaction rules are in genetic codes, there is experimental evidence that interactions between parts govern configuration of cells in some cases.(10)
10 C. Stern, Two or three bristles, American Scientist 42, 213-47 (1954). T. Gustafson and L. Wolpert, The cellular basis of morphogenesis and sea urchin development, Int. Rev. Cytol. 15, 139-214 (1963).
(Positive Feedback, MILSUM, QA 402 M5 1968, POSITIVE FEEDBACK : a general systems approach to positive/negative feedback and mutual causality, edited by John H. Milsum, McGill University, First edition 1968, )
(Positive Feedback, MILSUM, QA 402 M5 1968, ; pp.80-100, chapter 5, Mutual causality in general systems, Magoroth Maruyama, department of psychology, San Francisco State College, pp.90-92)
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• But the interaction has also a structure-stabilizing aspect. Let us look at the example of the grafted eye tissues again. When they were grafted on skin tissues, the skin tissues made the would-be-eye tissues into skin tissues counteracting against the possibility that the would-be-eye tissues might become an eye., chapter 5 of positive feedback, Mutual causality in general systems, Magoroth Maruyama; POSITIVE FEEDBACK : a general systems approach to positive/negative feedback and mutual causality, edited by John H. Milsum, pp.90-92.
Richard C. Francis., Epigenetics : the ultimate mystery of inheritance, 2011
the tissue-based theory of cancer
p.152
Mary Bissell and her colleagues at University of California, Berkeley, constructed an artificial breast-tissue environment that simulated the essential qualities of normal breast tissue in three dimensions. They then introduced malignant breast cancer cells into this environment and waited to see what happened. The result came as a surprise to many, though not to Bissell; the cancer cells were normalized.31 They lost their cancerous nature, in part through interactions with normal breast cells, arranged with the normal tissue architecture. But another important factor was the chemical composition of the extracellular matrix, the gel in which all cells are immersed. This gel is one of the primary ways through which cells chemically interact with each other during both normal development and cancer.
p.152
For Bissell and other advocates of the tissue-based theory, cancer should be understood as a disruption of normal development, a disruption which, in some cases, self-corrects. This self-correction can occur in either the stem cell environment or in fully differentiated tissue.
p.152
Cancer, from this microenvironmentalist view, results from the disruption of normal interactions between cells.
(Epigenetics : the ultimate mystery of inheritance / Richard C. Francis. ── 1st ed., 1. genetic regulation., 2. epigenesis., 3. adaptation (biology), QH450.F73 2011, 572.8'65──dc22, 2011, )
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