Ecosystems emerging: 6. Differentiation

An unlimited variety of within- and across-scale constraints generated by self-organizing processes in ecosystems presents problems for life to solve. Solutions reached at all levels of the ecological hierarchy spawn further constraints in an endless spiral of ecosystem growth and development. Diversification, exposed to natural selection, produces differentiated function within organized wholes. This paper reviews such differentiation over the span of organizational levels from atoms and biochemical molecules to cells and their genetics, from organs and organisms to species and their phylogenetics, from populations and communities to their compositions as ecosystems, and thence to the cosmos itself. On Earth, life occurs in non-extreme and extreme environments, enabled by a biphasic adaptive radiation that drills into and fills available niche space. The first phase is diversification, which is the generation of variations. The second phase is selective differentiation that sculpts meaningful function from an endless stream of diversified, niche-filling possibilities. The paper asks, from the apparent universality of this diversification/differentiation pair, whether or not there is a force in Nature that drives the phenomenon. Diversification arises more in atomism and differentiation in holism, in a part/whole resolution between particulate and aggregate spheres of existence. Examples from Okefenokee Swamp and extreme environments exemplify the two-phase process-deep sea, intertidal zones, carnivorous plants in nitrogen-poor conditions, insects in winter, and creatures of deep caves and, perhaps, subglacial lakes. Diversification (Darwin's generation of variants) and differentiation (via natural selection, and other agencies) of Nature's living forms is a prerequisite for Adaptation (our next installment) and the ultimate expression of (our final chapter) systemic Coherence. Liberation through in-system interaction, bonding, and coupling-all antithetical to degrees of freedom-is the paradoxical result.