HIERARCHICAL ORDER AND NEOGENESIS

"Hierarchical order," Grobstein said, "is no where more striking than in biological systems." He used Simon's analogy of Chinese boxes to describe hierarchical structures but developed from it a general equation. S=(A,B,C,..,N)R The set belongs to a system which is hierarchical when the set so defined has components which also are sets and when it itself is a component of a more encompassing set. In the above equation S is a set and A,B,C, and N are also encompassing sets. But it is R that is the most illuminating in discussing living and non-living systems. R is the relationship between the sets. It is whatever defines the set as a level in hierarchical order, In a simple aggregate (A)R=A, that is, the properties of A are not changed by the relationship R, This is not true of living systems, Living systems do not form aggregates, they form collectives. He listed two kinds of collectives, In facultative (reversible) collectives the properties of the elements are changed by being part of the collective, but they may be removed from the collective and they revert to their individual status. He used as an example colonies of bacteria whose members are altered in association but can be dispersed to return to individuals that may form another identical colony. Obligate collectives, once formed, may not be dispersed. In a complex multi-cellular organism special conditions are required to maintain individual cells or individual organs outside the collective relationship. He stated that, "The history of organisms and the history of the whole biotic mass has been one of successive production of higher and higher forms of obligate collectives." Organisms deal with the problem of replication of higher levels of order by replicating information at relatively low levels of orúder and then successively translating and transforming this information to generate higher levels of order. Biological order, as we have noted, exists as a number of levels in the living world, but fundamentally it is replicated at molecular- levels followed by re-establishment of higher orders through successive transformation of information into collectives at a higher level. The question that has eluded science since the Greeks is how order is re-established each new generation. In Grobstein's words, "As you knowú we are now thoroughly convinced that properties of successive generations are continuous, and that each generation begins with some amount of information which needs to be extensively processed before giving rise again to the maximum order of the fully formed adult. As an example of the mechanisms whereby higher orders are generated out of lower orders, he described the action of protein to enzyme transformation. A protein molecule is a linear array of amino acids on a polypeptide backbone. In water solution some side groups are hydrophobic and tend to move into the interior while others are hydrophilic and tend to remain on the surface. This causes a three-dimensional folding of the linear molecule according to the information programmed into it by the genetic information. This folding creates associations of sulfhydryl groups determined by the three-dimensional folding. We can summarize by saying that the interactive properties (in this instance catalytic or enzymatic) are an expression of the relationships among the amino acids, initially linear but secondarily complex. They are expressed in conformation, which is a transformation of the original linear sequence, sensitive to the context within which the molecule folds and functions. In the transformation to a higher order a new property emerges as the enzyme is formed. The point that Grobstein was making was that "In each instance of neogenesis the properties that appear during the origin of the new set are not the simple sum of the properties of the components that make up the set." The properties which characterize the set may depend on new relationships that might be established within the set, or with the context in which it functions. Essential to the understanding of neogenesis is an appreciation of the concept of emergence, As Grobstein so ably put it, "In fact, emergence can be understood, at the sacrifice of all the miracle but little of the fascination. Formal analysis shows that emergence relates to what may be called set-superset transitions." and finally, he said, "Hierarchical organization in biological systems thus is characterized by an exquisite array of delicately and intricately interlocked order. Steadily increasing in level and complexity and there- by giving rise neogenetically to emergent properties.

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