Fumio Tajima

, (born 1951) is a Japanese population geneticist known for his contributions to coalescence theory. He developed the test statistic now known as Tajima's D.

Biography Fumio Tajima was born in Ōkawa, in Japan's Fukuoka prefecture, in 1951. He graduated from high school in 1970, completed his undergraduate degree at Kyushu University in 1976, and received a Master's degree from the same institution in 1978. Tajima later stated that during his undergraduate degree he studied under Tsutomu Haga, and that he chose to study genetics after a meeting with him. In 1979 Tajima became a graduate student at the University of Texas in Houston, where he was supervised by Masatoshi Nei. He submitted his doctoral dissertation in 1983. Tajima returned to Kyushu university as a visiting scholar in 1983. Beginning in 1989, he worked at the National Institute of Genetics as an assistant professor and then an associate professor, before moving to the University of Tokyo in 1995.

As a graduate student, Tajima was one of several researchers working independently on coalescence theory, which seeks to describe the evolutionary history of a single locus. His training in phylogenetics and population genetics put him in a good position to explore evolutionary trees with respect to single loci.