Lilian Morgan was the first person to detect the attached X and closed X chromosomes. Morgan made these discoveries while investigating the Drosophila melanogaster's X chromosome. This information impacted genetics by offering evidence for the chromosome theory of heredity, which her husband, Thomas Hunt Morgan, and his colleagues were developing. Researching independently without the benefit of an institutional affiliation, Morgan was the sole author of ten scientific papers about her fruit fly discoveries. Geneticists such as Barbara McClintock benefitted from Morgan's research regarding attached X inheritance patterns. Morgan's work established a fundamental concept of genetics upon which other researchers elaborated, and aided geneticists in their efforts to confirm how organisms' characteristics are physically transmitted. Many basic genetics courses require students to demonstrate the principles outlined by Morgan.

Born in Hallowell, Maine, Morgan studied with cell biologist Edmund B. Wilson at Bryn Mawr College. Wilson considered Morgan one of...