CH13 network holoevolution

The modern synthetic theory of biological evolution describes the evolutionary process in terms of two fundamental phenomena—transgenerational descent, and modification of descent over time. However, it only recognizes one kind of descent, genetic descent, and one major modifying process, natural selection that is capable of steering genetic descent non-randomly toward adaptive, fitness-maximizing configurations. Other modifying processes, such as genetic drift and mutation, act at random. Thus, genetic fitness becomes a matter of genes contributed by ancestral organisms to descendants via germ-line inheritance. This "germ track" is separated from a corresponding body or "soma track" of non-heritable, mortal phenotypes by the so-called "Weismann barrier" (1885). In the post-Watson-Crick era of the second half of the 20th Century, this barrier came to mean unidirectional DNA —■ RNA —■ protein coding. It ensures that "nothing that happens to the soma can be communicated to the germ cells and their nuclei" (Mayr, 1982, p. 700). This is genetic determinism—the doctrine that the structure and function of organisms are exclusively determined by genes. The dogma has always been questioned, but it is now under serious re-examination in systems biology (Klipp et al., 2005) as evidence mounts showing the different ways environment controls gene expression. Environment is underplayed in conventional evolutionary theory, where it appears only as a non-specific agent in natural selection. The environment of environ theory is two-sided, and both sides can be seen to possess potentially heritable elements, enough to support the hypothesis that environment and genomes both code for phenotypes, one from inside, the other from outside. The term envirotype has been coined to convey this idea Patten (in prep), and so "holoevolution" (CH-13) postulates joint and balanced contributions to phenotypes, which are mortal, from two evolutionary, potentially immortal, lines of inheritance. These are the conventional genotype, engaged in bottom-up coding within the cell, and a corresponding external envirotype, manifesting top-down coding from without. Both input and output environs contribute to the heritable qualities of envirotypes, as outlined below:

• Input-environ-based inheritance. We can begin with the cell, and then mentally extrapolate outward through higher levels of organization to the organism and beyond. Each level, including that of the whole ecosystem, can be understood to have its own mechanisms of receiving environmental information, generating responses to this, and retaining (inheriting) through natural selection the ability to continue responses that prove beneficial to survival. Consider a cell receiving an energy- or matter-based signal from a near or distant source in its input environ. Biologist Bruce Lipton presents a scenario (http://www.brucelipton.com/newbiology.php) that effectively breaches the Weismann barrier and allows transmission of environmental data directly to the genome. Openness is at the heart of this process because the "cellular brain", as Lipton refers to it, is not located deep inside the cytoplasm or nucleus, but at the cell boundary. It is the cell membrane, or plasmalemma, a crystalline bi-layer of phospho-lipids and proteins that include a set of "integral membrane proteins" (IMPs) which serve as receptors and effectors. Receptor proteins respond to incoming molecules, or equally electromagnetic energy fields, by changing shape. This enables them to bond with specific effector proteins (enzymes, cytoskeletal elements, or transporters of electrons, protons, ions, or other chemical categories) that carry out behavior. If the requisite effector proteins are not already present in the cytoplasm, the IMP perception units activate expression of appropriate genes in the nucleus to produce new ones. New genes introduced into the DNA — RNA — protein sequence in the process remain behind to be copied, enabling the response to be repeated if adaptive, or ultimately fall obsolete and become consigned to the genomic set of inactive "junk" genes. Correct activations lead to life-enhancing behaviors, incorrect ones to maladaptation and death. Cellular adaptability thus becomes encoded in response to environmental inputs into new genes that encode new proteins, enabling survival in changing, but history-laden, environments. From the environ perspective, receptor molecules respond to signals transmitted in input environs, and effector molecules transmit the consequences to output environs. This initiates the second phase of environmental inheritance.

• Output-environ-based inheritance. When cells or other entities act on their environments the latter are changed as a result. This is "niche construction" Odling-Smee et al. (2003). Its essence is that it alters the machinery of natural selection because selection is, in the first instance, a manifestation of input environs. To the extent, however, that output environs generated by responses of their defining entities wrap around and become elements in those entities' input environs, the process becomes heritable, and epiphenomena such as autoevolution (Lima de Faria, 1988) emerge as distinct possibilities. Metazoan organization as "symbiogenic" aggregates of protozoan antecedents (Margulis, 1981, 1991) is an example. This is based on wrap-around feedback in which unicellular input- and output-environ overlaps are established in multicellular organization and achieve integration and identity. Organized cell communities possess self-similar IMP receptors responsive to the signal content of hormones and other intercellular regulatory macromolecules. This requires that output-environ elements become input-environ elements. Membrane proteins convert adjacent environmental signals into cellular "awareness", expressed as changes in protein configurations. The movements occasioned by these changes represent useful kinetic energy (exergy) that does the work of achieving further departure from thermodynamic equilibrium, which multicellular organization represents compared to unicells. This is the essence of all antientropic growth and development extending to ecosystems and the ecosphere. Each level has mechanisms peculiar to it for implementing environment-based inheritance and perpetuating all forms of life— operational genotype-phenotype-envirotype complexes—through time. Organisms and their cells below, and communities and ecosystems above, can be said to inherit both their contained genes and attached environments from ancestral forms, and to the extent that these environments manifest holism, the great panoply of life spread over the globe at all levels of organization can be seen as evolving jointly, altogether, in the ecosphere—"holoevolution."

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