The Evolution of Enzyme Specificity in the Metabolic Replicator Model of Prebiotic Evolution

The chemical machinery of life must have been catalytic from the outset. Models of the chemical origins have attempted to explain the ecological mechanisms maintaining a minimum necessary diversity of prebiotic replicator enzymes, but little attention has been paid so far to the evolutionary initiation of that diversity. We propose a possible first step in this direction: based on our previous model of a surface-bound metabolic replicator system we try to explain how the adaptive specialization of enzymatic replicator populations might have led to more diverse and more efficient communities of cooperating replicators with two different enzyme activities. The key assumptions of the model are that mutations in the replicator population can lead towards a) both of the two different enzyme specificities in separate replicators: efficient “specialists” or b) a “generalist” replicator type with both enzyme specificities working at less efficiency, or c) a fast-replicating, non-enzymatic “parasite”. We show that under realistic trade-off constraints on the phenotypic effects of these mutations the evolved replicator community will be usually composed of both types of specialists and of a limited abundance of parasites, provided that the replicators can slowly migrate on the mineral surface. It is only at very weak trade-offs that generalists take over in a phase-transition-like manner. The parasites do not seriously harm the system but can freely mutate, therefore they can be considered as pre-adaptations to later, useful functions that the metabolic system can adopt to increase its own fitness

Spirituality and giftedness type: A tale of adolescent variance

This chapter is an overview of the key discussions and findings from the author\u27s PhD thesis (Walton, 2015). Spirituality and its relation to giftedness are discussed, along with the theoretical framework for the research. The latter included applying the principles of Multiple Intelligences theory (MI) to the Differentiated Model of Giftedness and Talent (DMGT), creating the Differentiated Model of Multiple Intelligences (DMMI). An examination of the differences and commonalities in Australian gifted policies, with suggested categorisation, provided the background framing. Adolescents who were members of academic, creative and sporting gifted groups in schools in a large regional area of New South Wales (NSW) were surveyed on their views in relation to spirituality, along with a non-gifted control group. The key findings were: (1) significant variation in the spirituality of female gifted students, which were not reflected in the male responses; and (2) the Creative group scores were generally higher than the other groups, but this was not consistent across spirituality domains