Colin Pittendrigh

Colin Stephenson Pittendrigh (October 13, 1918 – March 19, 1996) was a British-born biologist who spent most of his adult life in the United States.

Pittendrigh is regarded as the "father of the biological clock," and founded the modern field of chronobiology alongside Jürgen Aschoff and Erwin Bünning.

He is known for his careful descriptions of the properties of the circadian clock in Drosophila and other species, and providing the first formal models of how circadian rhythms entrain (synchronize) to local light-dark cycles.

Colin Pittendrigh was born in Whitley Bay, on the coast of Northumberland (today Tyne and Wear) on October 13, 1918.

He obtained his botany degree from the University of Durham (King's College) in 1940.

Assigned to wartime service as a biologist in Trinidad during World War II, he studied malaria transmission by mosquitoes.

After the war, he attended Columbia University to study for his Ph.D.

He later joined the faculty of Princeton University and started his chronobiology research.

He received his first degree in botany in 1940 from University of Durham, now University of Newcastle upon Tyne.

Pittendrigh was a conscientious objector and so during World War II, he was assigned to wartime service to try and improve the production of bananas and other fruit that was being shipped to the UK during the war.

He also worked as a biologist for the Rockefeller Foundation and the government of Trinidad to control malaria near the military bases there.

He studied the epidemiology of malaria transmitted by mosquitoes breeding in epiphytic bromeliad ("tanks" formed by overlapping leaves) in the forest canopy.

He made acute observations on bromeliad distribution within forest canopies and between contrasting forest formations.

He observed daily rhythms in mosquito activity patterns, particularly noting that peak activity times were different for different species at different canopy levels.

His work with the biting rhythms of these mosquitoes was responsible for the development of his interest in biological rhythms, which later led to his experimental studies on eclosion rhythm in Drosophila.

Pittendrigh married Margaret "Mikey" Dorothy Eitelbach during the war.

Soon after, they moved to Trinidad and lived in the rain forest, where Pittendrigh worked on malaria control as part of the war effort.

He returned to the United States in 1945.

Margaret and Colin had two children, Robin Rourk, who currently lives in Louisville, Colorado and Colin Jr., who lives in Bozeman.

Pittendrigh had a grandson and a granddaughter.

Pittendrigh was an avid fly fisherman and outdoorsman, and he and his wife retired to Bozeman, Montana because of their love of the Rocky Mountains.

After the war, Pittendrigh attended Columbia University to study for his Ph.D. in biology under the evolutionary geneticist Theodosius Dobzhansky.

When he finished at Columbia in 1947, he joined the faculty at Princeton, as an assistant professor of biology where he began his work concerning circadian rhythms.

While at Princeton, he gained his U.S. citizenship in 1950 and served as dean of graduate studies from 1965 to 1969.

Pittendrigh also served on a variety of national scientific boards including the Science Advisory Committee to the Administrator of the National Aeronautics and Space Administration (NASA).

Pittendrigh met Aschoff in 1958 when Aschoff made his first visit to the United States.

Pittendrigh studied the eclosion rate of fruit flies, while Aschoff studied the continuous circadian rhythm of birds, mammals, and humans.

He also co-chaired a Mars exploration project at NASA from 1964 to 1966.

The defining principle that Pittendrigh developed throughout his career was that the properties of the circadian clock are independent from those of the behaviors it controls.

This gave him the freedom to study the clock through a range of physiological functions from the hatching of fruit flies to rodents' locomotor activities.

He performed large series of experiments to demonstrate that circadian rhythmicity is intrinsic and independent of environmental cues.

He carried out a famous and protracted debate with Frank Brown, of Northwestern University, on whether circadian timekeeping is intrinsic or environmentally driven.

Pittendrigh's data and argument ultimately prevailed and sparked interest in chronobiology.

In 1969 Pittendrigh left Princeton to join the faculty of Stanford where he helped found the program in Human Biology and later became the director of the Hopkins Marine Station.

While serving as the director of the Hopkins Marine Station in 1976-1984, Pittendrigh is credited with helping to rebuild Stanford's century-old marine biology laboratory, bringing in modern molecular biology, ecology and biomechanics, and turning the station into an internationally famous and vigorous one."

Pittendrigh retired from Stanford in 1984 and moved to Bozeman, Montana.

Here, he continued his studies of biological clocks, working with the faculty and lecturing at Montana State University – Bozeman.

Pittendrigh died from cancer on Tuesday, March 19, 1996, at his home in Bozeman, Montana.

He has been regarded as one of the most influential figures in the field, and his research influences the field of chronobiology even after his death.

The Society for Research on Biological Rhythms holds biennial lectures named in honor of Pittendrigh and Aschoff.