James Till

Dr. James Till is a Professor Emeritus at the University of Toronto's Department of Medical Biophysics. He attended the University of Saskatchewan, later graduating with a BSc in 1952 and a MSc in physics in 1954. Till proceeded to Yale University, where he received a Ph.D. in biophysics in 1957. He then became a post-doctoral fellow at the University of Toronto.

Soon after Till finished his work at Yale, Harold E. Johns asked him to join the Ontario Cancer Institute at Princess Margaret Hospital. Till ultimately made the decision to collaborate with Ernest McCulloch at the University of Toronto. Early in the 1960s, McCulloch and Till began a series of studies involving the injection of bone marrow cells into radio-treated mice. According to the number of bone marrow cells injected, they noticed that the mice's spleens developed tiny raised lumps in a proportional manner. The lumps were referred to as "spleen colonies" by Till and McCulloch, who hypothesized that each lump originated from a single marrow cell, possibly a stem cell.

In later work, graduate student Andy Becker collaborated with Till & McCulloch. They solidified their stem cell theory and reported their findings in Nature in 1963. They discovered evidence of these same marrow cells' capacity for self-renewal in the same year, working with Lou Siminovitch, a pioneer in Canadian molecular biology and a key component of the functional definition of stem cells they had developed.

In the 1980s Till's focus shifted, moving gradually into evaluation of cancer therapies, quality of life issues, and Internet research, including Internet research ethics and the ethics of List mining.

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