Thomas Hunt Morgan is best known for his work on heredity (huh•REH•duh•tee). Heredity is the passing on of traits from parents to children. Earlier scientists had many theories, or ideas, about this. They knew what happened, but they had only guesses as to how it happened. Morgan was among the first to use experiments to show how traits passed from one generation to the next. Today much work in genetics (juh•NEH•tiks), the study of how traits are passed from parents to offspring, is based on Morgan's ideas.








































Columbia University




























































Nobel Prize
      Thomas Hunt Morgan was born on September 25, 1866, in Lexington, Kentucky. As a boy he was interested in natural history, the science of living things. He enjoyed collecting nests, eggs, and fossils that he found. Morgan attended the University of Kentucky, where he studied zoology (zoh•AH•luh•jee), the science of animal life. He graduated in 1886 and continued his studies at Johns Hopkins University in Baltimore, Maryland. He received a doctoral degree in biology in 1890.
      Dr. Morgan worked and taught at Bryn Mawr College, near Philadelphia, Pennsylvania, for several years. He focused on embryology (em•bree•AH•luh•jee), the study of how animals develop at the very early stage when they are called embryos (EM•bree•ohz). In 1904 Morgan married one of his Bryn Mawr assistants, Lillian Sampson. Later that year he took a job as the head of the experimental zoology department at Columbia University in New York City.
      Morgan's most famous work took place during his 24 years at Columbia University. At that time, Morgan did not believe some of the well-known theories about heredity. One of his objections was that although scientists described what happened when traits passed from one generation to the next, they only made guesses as to how this actually worked. Morgan felt that the how behind these theories should be tested and proved through experiments. By 1909 he was studying heredity in a type of tiny fruit fly called Drosophila (droh•SAH•fuh•luh). Through years of research, Morgan was able to learn more about exactly how traits are passed from parents to their offspring. He showed that chromosomes, or tiny bodies of cells, carry hereditary information. He proved, too, that genes are parts of chromosomes, and that individual genes can determine individual traits. He showed that some traits are linked—that when an offspring gets one trait, it also gets the other. He also showed that some traits are "sex-linked," which means that they are passed only to males or females.
      Thomas Hunt Morgan was able to work quickly and effectively for several reasons. First, his choice of the fruit fly as an experimental subject was an ideal one. Drosophilas are cheap and easy to raise. They have short life spans, they reproduce quickly, and it is easy to tell the males from the females. Researchers who chose plants or other animals as their subjects had a more difficult time with their work. Second, Morgan gathered around him a team of talented assistants and co-workers known as the Morgan school. Morgan was always willing to share the group's successes, and when he made a mistake, he was quick to say so. When his research actually proved a theory he was trying to disprove, Morgan admitted it, made the necessary changes in his plans, and kept going. Finally, Morgan did his research in two ways, not just one like other researchers of the time. He used statistical analysis, keeping count of when and how many times a trait occurred, and he used a microscope to study why things happened the way they did.
      Thomas Hunt Morgan received many honors for his work, including the 1933 Nobel Prize for Physiology or Medicine. For many years Morgan continued his research, wrote books and articles about his work, and shared his ideas with others. He died in 1945 at the age of 79.