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 my opinion (as a non-biologist), she is entirely correct about that.
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.
Perhaps it challenges the strawman version of Darwinism that creationists and ID proponents love to criticize. But I don’t see it as any challenge at all to Darwinism.
West-Eberhard’s ideas are crucial for one main reason: The Darwinian project is intended, more than anything else, to demonstrate that teleology, or purpose, can be eliminated from our theoretical understanding of the living world.
Barham must have been listening to too many creationists. I am not aware that there is any such intention. As I understand it, the intention is to understand biological systems as well as possible. To this end, scientists will always prefer a mechanistic explanation over a teleological explanation. It’s not an attempt to eliminate teleology. It’s just that mechanistic explanations are more useful for the scientist.
West-Eberhard’s work helps to upend that project by showing how purposiveness (or goal-directedness) lies at the heart of any realistic explanatory framework in evolutionary biology. In other words, her contribution consists in demonstrating that, far from eliminating purpose from nature, evolution in fact presupposes it.
In a nutshell, West-Eberhard’s thesis is contained in the title of her magnum opus, Developmental Plasticity and Evolution (Oxford UP, 2003).
What is developmental plasticity? It is the property that all living things possess of being able to compensate during ontogenetic development for variations in either internal or external conditions. Note that “compensation” is a teleological concept. It implies that there is a particular end- or goal-state that one is trying to attain by means of the compensatory maneuvers.
I don’t think there is anything here that is new to biologists. They have even coined the term “teleonomy” for this sort of thing. However, contrary to Barham’s claim, it does not require a particular end or goal state. It requires only that development uses trial and error methods to maintain a suitable equilibrium.
In the case of an organism, the developmental process is aiming at the viable adult form. If a perturbation occurs during this process—be it genetic, physiological, or environmental—then compensatory changes will occur elsewhere within the organism to ensure, insofar as possible, that the viable adult form is reached in spite of the perturbation.
But this is surely false, as stated. Feedback system in the development process result in development often ending in a viable state, but not in the viable state. If there is a development defect in early development, there is no compensation to correct that defect, even though doing so might actually be simple. Babies are born with cleft palate, which could easily be corrected during development were the processes directed to a particular outcome. And there are still born babies and naturally aborted fetuses, neither of which should be expected if there were a particular goal.
Barham quotes West-Eberhard as saying:
Phenotypic plasticity enables organisms to develop functional phenotypes despite variation and environmental change via phenotypic accommodation—adaptive mutual adjustment among variable parts during development without genetic change.(2)
You can clearly see the difference there. She is not talking about a particular outcome. She is not talking about being directed to achieve the adult form. She is only saying that development tends to produce something functional. That’s far weaker that the teleology that Barham is describing, and that’s why biologists prefer to use the term “teleonomy.”
Toward the end of his post, Barham says:
To avoid teleology, Darwinism must posit random genetic changes that result in random phenotypic changes. But West-Eberhard’s work shows us there is no such thing as a random phenotypic change. Instead, we can now see that all phenotypic change is goal-directed.
But that’s just wrong. Avoiding teleology is not the goal. Darwinists don’t posit random genetic changes – they observe them. And if phenotypic change is less random, that’s because of natural selection, and of selective processes that are part of development.