Faces of Penn State: Masatoshi Nei
Evan Pugh Professor of Biology
Evan Pugh Professor of Biology and Director of the Institute of Molecular Evolutionary Genetics Masatoshi Nei’s 1972 paper on measuring the genetic differentiation between species (Nei’s Genetic Distance) is still one of the most cited papers in science. He applied this technique to human populations and obtained the first genetic evidence pointing to the African origins of modern humans.
Matasoshi Nei has always wanted to know how things worked. As a little boy, he dismantled his father’s grandfather clock, and then realized he couldn’t put it back together.
That didn’t slow him down. Growing up in Japan in the 1940s, he saw the damage of U.S. bombs dropped on his father’s farm and a nearby village. He wanted to see how the bombs worked, so he explored bomb sites and collected the ignition systems. They were “a bit complicated,” but the curious 14-year-old was undaunted.
When he tried to open one of the devices, it exploded in his hands, causing him to lose the vision in his left eye. “I wanted to know how it worked,” he explained, cupping his hands as if he were still holding that ignition system.
Nei has founded and developed an entire school of thought on molecular evolution, his career benchmark coming in 1972 with his measurement of the genetic differentiation between species, referred to as “Nei’s Genetic Distance.” This measurement makes it possible to estimate the origins of populations and the times of their divergence from common ancestors.
Nei’s theory of neighbor joining has also sparked a lot of attention in the molecular-evolution world. The theory allows scientists to genetically map and group closely linked species (genetic neighbors) and to join them by finding the next-closest genetic link. His next goal is to find out why. “We can infer that humans and monkeys diverged about 23 million years ago,” says Nei. “But that doesn’t tell you why that morphological difference evolved. I am more interested in why humans and monkeys have 10 fingers, but when you go back far enough, fish don’t have fingers.”
Nei’s search for answers has garnered him an impressive list of achievements and awards, including election as an honorary member of the Genetics Society of Japan in 1989, as a fellow of the American Academy of Arts and Sciences in 1990 and the U.S. National Academy of Sciences in 1997, and as an honorary member of the Japan Society for Histocompatibility and Immunogenetics in 2000. He also is co-founder of the Society of Molecular Biology and Evolution. An Evan Pugh Professor at Penn State, he is the founding director of the Institute for Molecular Evolutionary Genetics. Last year Nei was awarded the International Prize for Biology by the Japan Society for the Promotion of Science—an event that included an audience and dinner with the emporer and empress of Japan.
Suzan Erem
