Jeffrey C. Hall, Michael Rosbash and Michael W. Young were awarded the Nobel Prize in Physiology or Medicine on Monday for discoveries about the molecular mechanisms controlling the body’s circadian rhythm.

The three scientists used fruit flies to isolate a gene that controls the rhythm of a living organism’s daily life. Dr. Hall, Dr. Rosbash and Dr. Young were “able to peek inside our biological clock,” helping “explain how plants, animals and humans adapt their biological rhythm so that it is synchronized with the Earth’s revolutions,” the Nobel Prize committee said.

By examining the internal workings of fruit flies, the investigators helped determine that the gene they were analyzing encoded a protein that accumulated in cells at night, and then degraded during the day.