Leigh Van Valen

Leigh Van Valen died on October 16, 2010 of pneumonia at St. Mary of Nazareth Hospital Center in Chicago, Illinois. Van Valen had been hospitalized for more than three months from a rare form of fungal pneumonia, complicated by a long-standing but slowly progressing form of leukemia.

Van Valen also defined the Ecological Species Concept in 1976, in contrast to Ernst Mayr's Biological Species Concept. In 1991, he proposed that HeLa cells be defined as a new species, which was named Helacyton gartleri.

Amongst other work, Van Valen's proposed "Law of Extinction", known as Van Valen's law, drew upon the apparent constant probability (as opposed to rate) of extinction in families of related organisms, based on data compiled from existing literature on the duration of tens of thousands of genera throughout the fossil record. Van Valen proposed the Red Queen Hypothesis (1973), as an explanatory tangent to the Law of Extinction. The Red Queen Hypothesis captures the idea that there is a constant 'arms race' between co-evolving species. Its name is a reference to the Red Queen's race in Lewis Carroll's Through the Looking-Glass, in which the chess board moves such that Alice must continue running just to stay in the same place.

Leigh Van Valen (August 12, 1935 – October 16, 2010) was a U.S. evolutionary biologist. At the time of his death, he was professor emeritus in the Department of Ecology and Evolution at the University of Chicago.

Leigh Van Valen was born on Aug. 12, 1935, in Albany, NY and was chosen "most academic" in the first grade. He earned a zoology and botany degree at age 20 in 1955 from Miami University in Ohio. As a graduate student at Columbia, he studied under George Gaylord Simpson and Theodosius Dobzhansky, both giants in honing the synthetic theory of evolution, which melded Darwin's ideas about evolution with Mendel's on genetics. Van Valen met and married Phebe May Hoff while they were both doctoral students in biology at Columbia University. They had two children, girls Katrina and Diana. They divorced in 1984 after a long and friendly separation. Van Valen then married Virginia Maiorana, and eventually separated from that relationship as well. His last great love, with whom he was engaged to be married, was Towako Katsuno, a Japanese professor of Geriatric Nursing. They met when she came to Chicago to do her PhD.