A short selection from Essay Twelve in Darwin, Dogen, and the Extremophile Choice
The heavy is the root of the light. The unmoved is the source of all movement. Thus the master travels all day without leaving home. However splendid the views, she stays serenely in herself. Why should the lord of the country flit about like a fool? If you let yourself be blown to and fro, you lose touch with your root. If you let restlessness move you, you lose touch with who you are. —Lao-Tzu [1]
Unborn, undying, and inspired rather than aged by the winds of change, a species ‘family tree’ flickers and fluctuates like (to mix similes) an enduring flame through countless deaths and births. But we must step back further, far beyond local family trees and even beyond their speci-fied perimeters, in order to watch diverse genepool vines extend through their loosely interwoven lifetime cross sections; for it is here we witness the true, and irreversible, branching of Life’s phylogenic tree. From this grand Darwinian view, even the manifold flickering of true forest-tree populations that span many human lifetimes is but a brief testament to their deep past of adaptive radiation, during which occasional loose strands trailed off into non-interbreeding species. What mortal tree sports leaves as various as the siblings on a family tree, let alone the diversity in a forest of species?
It’s ironic and confusing that the best image we can call upon to represent the branching progress of phylogeny is a tree: an ontogenically programmed organism recycled from soil-made seed and back to soil again. It’s difficult enough to keep the intentional category errors of analogy and metaphor in line without adding to them unintended errors of scale. Since the book you have before you is an attempt to extend this difficult cross-scale analogy so as to shed some light on phylogeny’s one truly comparable process—the evolution of culturally-selected behaviour—I must now qualify my use of the conventional tree image (or ‘bush’ [2], as Stephen Jay Gould would have it) to reclaim its instructive power. Even if it turns out you can’t accept my phenomenological ‘evidence’ for this singular correspondence (for I acknowledge that it’s not only impossible to objectively verify reports on internal phenomena that are by definition subjective, but that my full-body Zen perspective runs counter to the mostly visual-graphic foundation of traditional science), nevertheless you might find that the ‘tree’, as amended in this section by the evo-ecological evidence alone, reflects an oddly familiar light back on ourselves.
Notes:
1. Darwin, 1968, The Origin of Species, Natural Selection, p. 136.
2. The original view of speciation assumed a certain degree of geographical isolation between two populations of a single species, which allowed for character displacement, followed by renewed contact; and from here it was supposed that competitive exclusion takes over. Throughout this book I am favouring a view closer to Paul Colinvaux’s (2007, pp. 121-122.) which gives far more credit to the subtlety of co-evolution. Isolation needs not be so crudely “geographical” in very large and complex ecosystems. It is still generally assumed that novel traits favouring the exploitation of new resources, at the expense of more species-typical resources, will get quickly diluted by the interbreeding of a large population. But it was demonstrated by Patrick Bateson as early as 1982 (Gould, 1995, pp. 379-380, “The Great Seal Principle”) that sexual selection goes beyond the establishing of overt traits to ensure advantageous mating; and in fact a general rule for perhaps all sexual species is “maximal attraction to intermediate familiarity”. It’s understandable that avoidance of breeding with close family is adaptive, but why is mating with intermediate family more adaptive than mating with more distant relations, unless selection for racial disparity is at play here? Nature seems to have evolved ways to get around even “novelty dilution”, so who are we to insist on a model of speciation simply because it’s crude enough for us to represent?
