V. Life's Corporeal Evolution Develops, Encodes and Organizes Itself: An Earthtwinian Genesis Synthesis

A. A Major Emergent Evolutionary Transitions Scale

West, Stuart, et al. Major Evolutionary Transitions in Individuality. Proceedings of the National Academy of Sciences. 112/10112, 2015. A paper for the 2014 NAS Sackler Colloquium entitled Symbioses Becoming Permanent: The Origins and Evolutionary Trajectories of Organelles about confirmations of life’s communal emergence as due to pervasive symbiotic unions. In accord with Eors Szathmary’s presentation at this meeting (search), this nested, manifest scale could be seen as regnant, liberated persons in relative communities.

The evolution of life on earth has been driven by a small number of major evolutionary transitions. These transitions have been characterized by individuals that could previously replicate independently, cooperating to form a new, more complex life form. For example, archaea and eubacteria formed eukaryotic cells, and cells formed multicellular organisms. However, not all cooperative groups are en route to major transitions. How can we explain why major evolutionary transitions have or haven’t taken place on different branches of the tree of life? We break down major transitions into two steps: the formation of a cooperative group and the transformation of that group into an integrated entity. We show how these steps require cooperation, division of labor, communication, mutual dependence, and negligible within-group conflict. We find that certain ecological conditions and the ways in which groups form have played recurrent roles in driving multiple transitions. In contrast, we find that other factors have played relatively minor roles at many key points, such as within-group kin discrimination and mechanisms to actively repress competition. More generally, by identifying the small number of factors that have driven major transitions, we provide a simpler and more unified description of how life on earth has evolved. (Abstract)

Wilson, David Sloan, et al. Multilevel Selection Theory and Major Evolutionary Transitions. Current Directions in Psychological Science. 17/1, 2008. As this synthesis gains acceptance, human persons can be seen poised for a further integration into various organism-like group assemblies which can take on a modicum of their own cognition and mind, surely an occasion of import for psychologists.

When between-group selection dominates within-group selection, a major evolutionary transition occurs. The social group becomes a higher-level organism and the members of the group acquire an organ-like status. This idea was first proposed to explain the evolution of eukaryotic (nucleated) cells, not by small mutational steps from prokaryotic (bacterial) cells but as highly integrated symbiotic associations of bacteria. The idea was then generalized to include other major transitions, including the first cells, multicellular organisms, social insect colonies, and even the origin of life as groups of cooperating molecular interactions. (7)

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