In the first four installments of this series, I looked at evidence leading us to reject the machine metaphor and Darwinism as an inadequate theoretical perspective on life.

This evidence mainly consisted in examples of unexpected plasticity, or adaptive capability, in whole-organism behavior.

In installment five, I began exploring an alternative view of life as an emergent phenomenon within an overall framework of physical emergence that has been developed by investigators in condensed-matter physics over the past half century.

Last time, I began the task of exploring specific ideas that have been proposed by various scientists as an alternative explanation of the intelligent agency and adaptive capability that constitute the essence of life.

In particular, I looked at UCLA physiologist F. Eugene Yates's notion of homeodynamics. This theory, or heuristic, borrows concepts from nonlinear dynamics in order to provide a more adequate description of the actual behavior of living systems than that offered by traditional computational and cybernetic models and theories.

Last time, I discussed the concept of emergence as a general background for understanding life.

I proposed that the best way to think of emergent phenomena in this connection is in the way that condensed-matter physicists do.

Namely, qualitatively new entities and properties arise  due to symmetry breaking, and new effective fields emerge as we move from one level to another up the hierarchy of nature. Effective fields, according to quantum field theory (QFT), are fields with properties that are specific to a particular level, or length scale. This is the "more is different" principle.

I also stressed that the thing, above all, that we should be seeking to explain in biology is the functional stability of the cell (or any living organism). That means the way the chemical reactions that constitute the physiology, or "metabolism," of a cell are teleologically organized---directed towards the cell's own self-preservation.

In addition, every living thing has the capacity to react appropriately so as to compensate (within limits, of course) for internal or external perturbations. I have been calling this capacity "adaptivity," and the general power of the cell to strive and act on its own behalf, "intelligent agency."

Natural genetic engineering genetic engineering in bacteria.

Bipedal goats and dogs.

Maze-solving slime mold, ferrets that see with their auditory cortex, fruit flies with inverted visual fields, and humans who "see" with their tongues.

These are some of the phenomena I've looked at in previous weeks in order to make the case that living beings possess a general ability to respond to challenges by means of appropriate compensation or adaptation.

I've been arguing that the existence of such a general power of "adaptivity" or "intelligent agency" cannot be explained by the theory of natural selection, but rather is the tacit presupposition that gives that theory its superficial plausibility.

But if natural selection cannot explain this power or capacity, what can?  How is it possible for a physical system---the cell---to possess such a remarkable property? How can we best try to understand it scientifically?

Once we finally succeed in freeing our minds from the Darwinian style of thinking, our real work has only just begun.

Last week, I looked at the work of Mary Jane West-Eberhard on the contribution that developmental plasticity makes to evolution.

In particular, I reviewed examples like Slijper's goat and Faith the Dog, in which a severe perturbation at the genetic level results in a truly stunning compensation at the level of the adult phenotype.

Such cases provide a vivid illustration of the general principle that no novel phenotype that is presented to selection is ever truly random, because in between the genetic variation (which may be random, though not necessarily so) and the new viable adult phenotype there always intervenes a decidedly non-random, goal-directed developmental process.

This fact, in turn, means that the theory of natural selection derives whatever plausibility it has largely from the unspoken assumption that when you perturb the living organism, it will compensate as best it can.

Mary Jane West-Eberhard (left) is both brilliant and quietly subversive, but she is no firebrand.

Unlike the subject of my previous column in this series, James A. Shapiro, she does not present her ideas as revolutionary or as a mortal threat to the Darwinian worldview.

In fact, she goes out of her way to associate her ideas with those of Darwin himself, which were in some respects more radical that those of his twentieth-century epigones.(1)

And yet, I shall argue that West-Eberhard---who is a researcher at the Smithsonian Tropical Research Institute in Panama, as well as a professor of biology at the University of Costa Rica---has made a foudational contribution to a new and revolutionary approach to evolutionary theorizing that bids fair (whatever her expressed intentions) to turn mainstream Darwinism on its head.