Choreography for the Birds
Order in nature is often less intelligent than it appears.
Posted Feb 07, 2018
When Darwin was a young man, religious people took to the hills, fields, streams, and moors to pursue enthusiasms for birds, butterflies, and flowers (1). Appreciation of nature was a way to praise the creator.
We should not be too surprised that Darwin was affected by this religious enthusiasm. After all, he fully expected to take up his occupation as a clergyman. Natural theology highlighted the exquisite match between each species and the way that it makes its living, something we now refer to as adaptation.
Watchmaker and Watch
One of the most influential natural theologists of the time was William Paley who promoted creationism using clever rhetorical turns that are superficially convincing but lack logical validity (1).
One of Paley's favorite metaphors was of the creator as a watchmaker, and the natural world as a clock. If one comes across a beautiful work of engineering, such as a fine watch with its delicate springs and escapements, it is obvious that there has to be a watchmaker, he argued. (The case that design in nature calls for a creator is referred to as the argument from design).
Of course, this argument is pure sophistry but that has not prevented contemporary creationists from repeating it in various forms. To begin with, the argument is circular because we already knew that watches are made by watchmakers and the inference that this would apply to something completely different is bogus. Any conclusion about man made objects has zero relevance for living organisms that are not man made.
Such deductive errors can be surprisingly compelling, a fact that casts doubt on the robustness of human reasoning. Although logically flawed, such arguments from design are emotionally satisfying and the emotion often wins out (2).
Whereas natural theology used the natural world as supportive evidence for theological claims, Darwin's theory of evolution undercut such claims. If natural selection could explain why animals are ideally matched to their ecological circumstances, then it removed the benevolent creator from the picture. In other words, the “why” of theology was overtaken by the “how” of natural selection. With the mechanism of natural selection in place, there was no need for a creator.
Natural theology may be a footnote in history but it illustrates a strong human tendency to ascribe central agency and control to phenomena that may lack either. Coordinated movements of social animals are a case in point.
The Dance of the Starlings
Huge flocks of starlings can wheel in unison around the sky in coordinated movements that recall the terrestrial feats of human choreographers. Dance troupes require detailed drilling and practice and use a musical score to keep in time, however. How do starlings achieve such order in large flocks?
Starlings are not alone in their coordinated group movements. Schooling fish do something similar beneath the surface of the water (2). Acting as a unit in this way may confuse, or intimidate potential predators. Or, it could simply be a manifestation of the principle that there is safety in numbers because members of a large school are less likely to be taken in an attack than an isolated fish is.
Either way, the underwater ballet is an impressive phenomenon from the point of view of individuals timing their movements perfectly to match the direction and speed of the group.
Such accomplishments were a mystery, given that there is no one calling the dance, so to speak. No centralized mechanism of control applies. Now, it is becoming clear that the coordination is an emergent property of the actions of individuals, coordinated movement of large numbers of individuals rather than the result of centralized control (2). They are said to be “self-organized.”
Fish have sensitive pressure detectors on the sides of their bodies, known as lateral line organs, that are exquisitely sensitive to local disturbances in the water and allow individuals to adjust their moves to avoid colliding with neighbors. Similarly, birds use mostly visual cues to avoid midair collisions. In each case, the result is an illusion of centralized control where none actually exists.
The Human Analog of Starling Choreography
Although we now know that there is no starling choreographer, no lead bird, their aerial acrobatics create a strong impression of top-down leadership and control.
That cognitive bias likely exists because of the need to distinguish friends from foes. We are therefore very willing to ascribe motives to others that may not be accurate but can help us to form alliances and avoid trouble.
Just as Darwin's contemporaries were happy to ascribe the match between species and their way of life to the actions of a benevolent creator, we are still inclined to see the natural world as a great deal more intelligent, and more deliberate, than it actually is.
A striking example of this emerged in modern evolutionary biology when scholars began talking about “selfish genes (4),” an unfortunate metaphor that cast a cloud of confusion over a generation of students and scholars. In reality, genes do nothing more than supply the recipe for protein molecules and are expressed under restricted biochemical circumstances (5). They can't be either selfless, or selfish.
Even if starlings need no director to wheel in unison through the sky in vast flocks, it remains an impressive spectacle. We can all agree to enjoy the show.
1 Ruse, M. (1982). Darwinism defended: A guide to the evolution controversies. London: Addison-Wesley.
2 Kahneman D. (2011). Thinking fast and slow. New York: Farrar, Straus and Giroux.
3 Hemelrijk, C. K., and Hildenbrandt, H. (2012). Schools of fish and flocks of birds: Their shape and internal structure by self-organization. Interface Focus, 2, 726-737.
4 Dawkins, R. (1976). The selfish gene. New York: Oxford University Press.
5 Blumberg, M. S. (2009). Freaks of nature: What anomalies tell us about development. New York: Oxford University Press.