Alfred Day Hershey
Alfred graduated from Michigan State in 1930 with a B.S and in 1934 with a Ph.D. Hershey accepted a position as an instructor at the Washington University School in Medicine, where he started working on bacteriophage. There weren't many people working on bacteriophage. Two scientists who read Hershey's papers, Max Delbruck and Salvador Luria, were collaborating on experiments using bacteriophage. In 1946, while working with Delbruck, Hershey discovered that phage can recombine when co-infected into a bacteria host. Delbruck, Luria, and Hershey established the American Phage Group. This organization had a tremendous influence on bacteriophage research.Hershey accepted a position from the Carnegie Institution of Washington's Department of Genetics at Cold Spring Harbor in 1950. Here he and Martha Chase did Hershey-Chase blender experiment that proved phage DNA was the genetic material. For this and all his work on bacteriophage, Hershey shared the 1969 Nobel Prize for Physiology Medicine with Max Delbruck and Salvador Luria. In 1962, Hershey became the Director of the Genetics Research Unit at Cold Spring Harbor Laboratory, and continued to work on bacteriophage. In 1974, Hershey retired, and in 1979 a building on the grounds was dedicated to him.
Barbara was born on June 16, 1902, in Hartford, Connecticut being one of the four children in her family. She graduated from Erasmus Hall High School in 1919. McClintock earned her B.S and M.S. degrees in botany at Cornell University, and received her Ph.D in the subject at Cornell in 1927. Even though women were not allowed to major in genetics at Cornell, she became a highly influential member of a small group that studied maize cytogenetics, the genetic study of maize at cellular level.
In the early 1930's, fellowships from the National Research Council, the Guggenheim Foundation, enabled Dr. McClintock to pursue genetics research at several different institutions. Part of this training included six months in Germany in 1933-1934, but political tensions across Europe forced her to return to the United States earlier. Throughout her long and distinguished career, her work focused on the genetics of maize and the relationship between plant reproduction and subsequent mutation. In December of 1941, she was offered a one-year research position at the Carnegie Institution, in which turned into a full time position. In the late 1920's, she studied how genes in chromosomes could "move" during breeding of maize plants. She did groundbreaking research on this phenomenon, which determined the physical correlate of genetic crossing-over. Later during 1940's and 50's she showed how certain genes were responsible for turning on or off physical characteristics. In 1957, McClintock received funding from the National Science Foundation and the Rocketfeller Foundation to study different varieties of maize in South and Central America. McClintock and her colleagues spent two decades assembling data on differences in South American maize, which were finally published in 1981 as The Chromosomal Constitution of Races of Maize.In 1976, McClintock retired from the Carnegie Institution, which awarded her a Distinguished Service Award. McClintock was recognized as one of the most distinguished scientists of the 20th century. She was the 3rd woman elected to National Academy of Sciences, the first woman to become president of the Genetics Society of America. In 1971 President Richard Nixon awarded her the National Medal of Science. She was given the Albert and Mary Lasker Award. In 1983, at the age of 81, she received the Nobel Prize in Physiology of Medicine for her work on "mobile genetic elements." McClintock died at the age of 90.
Mendel discovered the basic principles of heredity through experiments in his garden. Mendel's observations became the foundation of modern genetics and the study of heredity.In 1853, upon completing his studies at the University of Vienna, Mendel returned to the monastery in Brno and was given a teaching position where he would stay for more than a decade. Around 1854, Mendel began to research the transmission of hereditary traits in plant hybrids. At the time of Mendel's studies, it was a generally accepted fact that the hereditary traits of the offspring of any species were merely the diluted blending of whatever traits were present in the "parents." After analyzing his results from his pea experiment, he reached his most important conclusions: the Law of Segregation and the Law of Independent Assortment. In 1868, Mendel was elected abbot of the school where he had been teaching. He traveled little during this time, and was further isolated from his contemporaries as the result of his public opposition to and 1874 tax law. Gregor Mendel died on January 6, 1884, at the age of 61, His work however, was still largely unknown. It wasn't until decades later, when Mendel's research informed the work of several noted geneticists, botanists, and biologists conducting research on heredity, and his studies began to be referred to as Mendel's Laws. As genetic theory continued to develop, his research and theories are considered fundamental to any understanding of the field, and he is considered the father of modern genetics."