An Unusually Creative Place

In 1987 I had the privilege of earning my Ph.D. at the University of Illinois in what was at that time called the School of Life Sciences. Having nothing else to which to compare it at the time, I did not realize what a privilege it was.

At that time, the biology faculty at the U of I included some truly creative thinkers, who were not merely competent at advancing knowledge in their fields but also investigated the connections among different fields of intellectual inquiry. That is, these remarkable individuals contributed greatly to what E. O. Wilson calls consilience. I would just like to mention a few of them here.

One of them was my advisor, the late Fakhri A. Bazzaz. He saw plant ecology as a complex and global set of processes that included human effects on the natural world. He was interested in anything and everything that affected plants and anything and everything that plants did in the world. He brought together graduate students and professional collaborators who were interested in ecophysiology, population genetics, conservation, plant reproduction, coevolution, and global climate change. He was not the world leader in any of these fields, but was incomparable in bringing them together. He was always enthusiastic. His booming happy voice was a mainstay of our lab.

Another unusually creative person at Illinois was the late Carl Woese (see my earlier essay about him). He was good at doing the (at the time) tedious work of determining base sequences of microbial genes. But his goal was to understand the evolution of all of life. This is what led him to recognize the Archaea as a separate line of evolution. But he also speculated about the origin of life and how evolution fit in with the basic physical processes of the universe. I took a seminar from him in which we discussed some basic ideas about evolution, including some possible overlaps with eastern religion and philosophy.

Another such person was Mary Willson, who now lives in Alaska. She first showed her creativity by moving her research interest from birds to plants (which she called “sessile green birds”). She was looking for ideas that united evolutionary lineages as unrelated as plants and birds. One of those was sexual selection. She, along with Nancy Burley, was one of the pioneers in the study of sexual selection in plants. Most of us simply learned about double fertilization in flowering plants, in which one sperm nucleus fertilized an egg nucleus, producing an embryo, while the other sperm nucleus fertilized the two polar nuclei, producing a triploid endosperm. That’s just the way it is. Willson wondered why. If the endosperm is simply a source of food, to be eaten by the embryo, why should it be the product of fertilization? And, moreover, why should it be triploid? Did the double dose of genes from the female parent allow it some extra measure of control over the embryo inside the seed? A recent article in the Proceedings of the National Academy of Sciences provided some evidence that a close genetic relationship between embryo and endosperm facilitated altruism. This astonishing idea had its roots in what Mary Willson had written three decades earlier.

A fourth example is May Berenbaum, who is still a remarkably productive member of the U of I faculty and the National Academy of Sciences. Her enthusiasm for understanding the coevolution of plants and the insects that ate them spilled over into a zeal for opening the eyes of the public to an understanding of insects. She has written numerous popular books about insects, and about 1981 started what has become an annual tradition at the U of I: the Insect Fear Film Festival.

Of course, every faculty member I knew at Illinois in the 1980s was remarkably competent in their fields, a tradition that continues today. But these four individuals stood or stand out for their creativity. As a result, I was inspired to think creatively about the big picture, and to ask big questions, rather than to focus exclusively on a narrow range of research. What a remarkable privilege this experience was.

Passing the Consilience Test

In the cult classic movie Harold and Maude, Maude recites a quote, but cannot remember who had said it. “Oh, well,” she said, “I did.”

The statement “Extraordinary claims require extraordinary evidence” is now famous. I’m not sure who said it first—I have heard it was Carl Sagan, but I’ll bet he was quoting one of the giants on whose shoulder he was standing. What I wish to consider now is, what constitutes extraordinary evidence? An important kind of extraordinary evidence is consilience.

Consilience means that a theory has been supported by numerous, independent lines of evidence—independent, that is, unless the theory itself is true. William Whewell (pronounced “hule”) invented the term, and used Isaac Newton as an important example. Newton’s theories of motion and gravitation were supported by the movement of objects on Earth and of the planets. Whewell rejected the evolutionary theory of Charles Darwin, even though evolution has proven to be one of the premier examples of consilience. Evolution is supported by fossils, biogeography, the process of natural selection, and now by molecular evidence. Without evolution, there is no reason to expect that older fossil assemblages should be less similar to modern organisms than younger fossil assemblages, for large placental mammals to be absent from Australia and Borneo, or for chimps to have the same pseudogenes that we do.

There are numerous examples of consilience in the history of science, though few as important as evolution. One example is DNA. Watson and Crick figured out the structure of DNA not only from chemistry and crystallography, but also because this structure made it obvious how could replicate and how genetic information could be stored.

The newest example of massive consilience is the theory of global warming. It is a theory because it is assembled from numerous hypotheses, all of which have been tested and confirmed. Among the lines of evidence are:

• Direct temperature readings by thermometers in the last century and a half

• Direct carbon dioxide measurements from the atmosphere in the last half century

• Indirect temperature estimates from ice cores

• Carbon dioxide measurements from ice cores

• Melting of polar sea ice in the Arctic

• Melting of land ice in Greenland and Antarctica

• Rising sea levels (despite the refusal of the North Carolina legislature to permit it)

• Phenological changes in many species of animals and plants

• Warmer winters allowing insect outbreaks in coniferous forests

• Methane bubbling out of Siberian lakes that no longer freeze even in winter

• Storms of increased intensity in coastal areas

• Droughts of increased intensity and duration in continental areas

And so on. I have contributed some of the phenological data to the above list. (Plants and animals have become active earlier in the spring by about two days per decade or, in some local cases such as my data set, two days earlier per year.) There was a time, about thirty years ago, when global warming was an extraordinary claim that required extraordinary evidence. The evidence is now in, and it constitutes consilience. There is no reason to expect all of those separate lines of evidence to converge on the same theory unless the theory is true. Consilience can be thought of as the opposite of pseudoreplication, in which you measure the same thing over and over.

Edward O. Wilson has written many books of great significance, and you all know about most of them. In case you might have overlooked it, I wish to suggest his book Consilience. He indicated that evolution provides a framework for the consilience of all branches of knowledge. This claim was sufficiently broad and sweeping to evoke some strong responses, perhaps most notably from essayist Wendell Berry, who wrote Life is a Miracle in a sincere but, I think, failed attempt to refute Wilson. I am an immense admirer of Berry, but admit that he was wrong about this one.

It is interesting that the anti-science movement has fought against both evolution and global warming. They have taken on two of the aspects of modern science that not only have the most evidence, but the most consilience.