The Human Genome Project was first proposed at a conference in 1986 when scientists from the United States created plans to sequence the entire human genome. The project itself officially began in 1990.
The scientists who proposed the Human Genome Project were interested in the genetic basis of cancer and in DNA damage caused by the atom bombs dropped on Japan. The Human Genome Project was ended in April 2003 after successfully mapping the entire human genome. It revealed there are likely around 20,500 human genes, which was fewer than previously expected. The very first gene mapping was done in 1911 by Alfred Sturtevant working with Drosophila melanogaster, or the fruit fly.