Description of the biologicalhierarchy of the organism has been extendedhere to included the evolutionary andecological sub-hierarchies with theirrespective levels in order to give a completehierarchical description of life. These newdescriptions include direction of formation,types of constraints, and dual levels. Constraints are produced at the macromolecularlevel of genes/proteins, some of which (a) aredescendent restraints which hold a hierarchytogether and others (b) interact horizontallywith selective agents at corresponding levelsof the niche. The organism is a dual levelconstrained by both the ecologicalsub-hierarchy (survival) and (...) evolutionarysub-hierarchy (fitness) while serving as thehighest level of the specializationsub-hierarchy, therefore, it is unique inbelonging to three sub-hierarchies. Organismsexperience birth, sometimes death, andparticipate in evolution. Birth of an organismis realized when a cell is removed from theconstraints of the organism and assumes itsown organismal constraints. Death occurs withthe cessation of protein synthesis becauseproteins and their products constitutecomponents at high levels of the hierarchy. Selection is of two types, natural selection,involving adaptive traits interacting withfeatures in a niche, and hierarchicalselection, requiring traits to be compatiblewith existing hierarchical constraints. (shrink)

Emergent properties have been described by Mill, Lewes, Broad, Morgan and others, as novel, nonadditive, nonpredictable and nondeducible within a hierarchical context. I have developed a more definitive concept of a hierarchy that can be used to inspect the phenomenon of emergence in a new and detailed manner. A hierarchy is held together by descending constraints and new features can arise when an upper level entity restrains its components in new combinations that are not expected when viewing these components alone. (...) Examples of emergent features are matching anticodons and amino acids by aminoacetyl-tRNA synthetase enzymes appearing early among the first forms of life, negative feedback in end-product inhibition first occurring in microbes, memory in animals and apical cells in plants. Until recently, life was considered only in terms of physics and chemistry, but now it is known to have a third aspect of information that along with the descendant constraints in its hierarchical organization makes emergentism possible within a reductionist’s framework. (shrink)

Apical cells are universally present in lower plants and their description has been mostly viewed morphologically as single-celled meristems. This study attempts to demonstrate that the roles of apical cells and more generally of meristems collectively are (a) often the proliferative source of all cells in a plant, (b) sometimes a formative centre in histogenesis and organogenesis and (c) always a regulatory site. As a proliferative centre it occurs as a series of apical cells through a mitotic lineage by unequal (...) divisions which includes a rotational pattern to form cells distributed according to the symmetry of its organ. As a formative centre it determines leaf arrangement in mosses and leafy liverworts as well as the root cap and gametophyte cushion in ferns. It appears initially to determine the type of organ and later the organ determines the type of apical cells within. As a regulatory centre it activates distal secondary cells to proliferate as well as inhibiting neighbouring cells from becoming apical cells to preserve the identity of an organ during its development.Based on these three roles by which apical cells can be recognized an argument can be drafted that seed plants may have apical cells, although morphologically indistinguishable from other cells, singularly or in batteries instead of possessing the traditionally described multicellular meristems. (shrink)

Plants are interpreted as structural hierarchies which are real systems organized through descending constraints. Types of hierarchical groups in plants are (a) cluster by integration, (b) support through attachment, (c) enclosure by encasement (d) dissipative by input of energy and (e) control through variable state switching. Most plant hierarchies are mixtures of these types which explains a number of paradoxes in plant morphology. The traditional means of identifying levels, i.e., cell, tissues, organs, uses a compositional group which is not a (...) hierarchical group but a similarity feature and so is inadequate for describing hierarchies. Hierarchies can be defined by set theory which is more a description of cognitive than real hierarchies and therefore is of little value in describing plant organization. The hierarchical description of a plant emphasizes the immediate physical status of organization which provide, in turn, a physical explanation of development. (shrink)