Leigh Van Valen, professor emeritus of Ecology and Evolution at the University of Chicago, died last Saturday, October 16. An internationally renowned evolutionary biologist, Van Valen was the originator of the “Red Queen hypothesis” and a founder of the field of paleobiology.
From the official University of Chicago press release:
In his most famous paper, “A New Evolutionary Law,” published in 1973, he introduced novel observations and a radical interpretation that together continue to shape the field. The first, which he labeled the law of constant extinction—often called Van Valen’s Law—states that the probability of extinction for species and larger evolutionary groups bears no relation to how long it may have already existed. The fossil record, he argued, shows that lineages become neither more extinction-resistant nor more vulnerable over time.
To explain this surprising pattern, he proposed the Red Queen hypothesis, a model of co-evolutionary interaction, and one of the most enduring metaphors in modern biology. It holds that the struggle for existence never eases up, so that no species or lineage ever pulls ahead for long. Instead there is a constant arms race among species or larger groups, such as a community of competing lineages or parasites and their hosts. In a world with a fixed amount of energy, each must continually develop new adaptations, weapons or defenses to keep up with the other, a prolonged sequence of mutational one-upmanship.
Considered unconventional even by eccentrics, Van Valen had a wide range of interests, spanning the history of all life forms. “I don’t work linearly,” he explained in a note to his department chair. “I am a generalist and tend to open new approaches more than fill them in. What I work on changes irregularly and unpredictably with the progress of theory and knowledge.”
“Leigh Van Valen was an unbelievably broad thinker, uniquely so,” recalled his colleague David Jablonski, the William Kenan Jr. Professor in Geophysical Sciences. “The breadth of his work was staggering. He was interested in big questions—in everything, actually—but especially in topics like how diversity came about, how it changed over time.”
The picture that emerges of Van Valen is that of a divergent, even radical, thinker. Although capable of specific, technical, and highly theoretical research, he had the soul of a generalist, as evidenced by the wide range of interests he possessed (not to mention his own statements, seen above). As his colleagues and former students attest, he was a unique scientist, and he stood out even at a university that is known for having more than its share of offbeat and eccentric professors.
Van Valen’s work, as transmitted through his greatest popularizer–British science journalist Matt Ridley, was hugely influential on my own worldview and my scientific ethos. I read Ridley’s book The Red Queen: Sex and the Evolution of Human Nature my junior year in high school. I was enthralled by Ridley’s account of the development of modern evolutionary biology, and fascinated by the exciting yet painstaking research of Ridley’s protagonists, including W.D. Hamilton, John Maynard Smith, Donald Symons, and Leigh Van Valen. Even more than was already the case, scientists became my heroes, and professors became the men (like Albert Einstein and Stephen Hawking) and women (like Rosalind Franklin and Jane Goodall) that I esteemed. Although I soon decided that I found history far more interesting than biology (and would later decide that I found economics even more interesting than history, as my favorite parts of history tended to be economic history), I remained committed to the idea that I would dedicate my own life to scholarly inquiry. Thus, I owe the direction of my academic career to my reading of Ridley’s The Red Queen, and that book truly would not have existed but for the contributions of Leigh Van Valen.
Bryan Caplan has written (on more than one occasion) that he misses Julian Simon, even though he never met Simon. Well, I can say the same thing about Leigh Van Valen. Even though I (probably) never met you, I will miss you, Professor Van Valen!