Abstract: In this article I will try to explain the nature of biological rhythms, their history and their effect on the daily functioning of the human body and mind. Biological rhythms, known as circadian rhythms, or the internal clock, pervade every aspect of human and animal life. Defined as "the biological clocks that regulate all animals, plants, and people, and that do not follow the artificial timing of the rigid 24-hour solar/lunar day" ("Circadian Links," WWW 1996), biorhythms influence life ordinary daily life. activities in an extraordinary way. Even in the absence of light signals, human rhythms continue in remarkably stable patterns, and studies show that these patterns consistently adapt to an average 25-hour day. Biorhythms influence a huge amount of bodily functions, including heart rate, body temperature, mood, alertness, efficiency, pain sensitivity, and the effects of alcohol. They are also believed to influence birth and death patterns and even behaviors throughout a woman's menstrual cycle. In essence, biorhythms influence almost every human action or reaction anyone can imagine. Most of the early observations of how circadian rhythms work revolved around plants and small laboratory animals, namely bees, rats, and birds. Biorhythms were noted as early as the 4th century BC, when a scribe of Alexander the Great noted that there were rhythms surrounding the opening and closing of certain types of tree leaves. In 1729 the first experiment on biorhythms was conducted by Jean Jacques d'Ortous deMairan on the heliotrope plant. The plant's leaves, even in complete darkness, opened and closed in a stable day-night pattern. A taxonomist, Carolus Linnaeus, took advantage of flowers... the medium of paper... and even life and death. They are the root of sleep disorders and sleep disorders and also explain phenomena such as jet lag and insomnia. Even in isolation the human clock runs on a schedule close to that of a normal day. Studies and research continue to realize the full potential of daily biological planning and its effects on the efficiency of the mind and body. Works Cited “Circadian Links: Official Circadian Rhythms Website.” Internet, 2014. Cole, Roger J. “Jet lag and circadian rhythms.” Internet, 2014. Hunter, Maxey, and Yurasits. “Biotiming Tutorial.” Internet, 2014.Knutson, Kristen. “Center for Circadian Biology and Medicine.” Internet, 2014.Palmer, John D. An Introduction to Biological Rhythms. New York: Academic Press, 2006.Winfree, Arthur T. Biological Clocks. New York: Scientific American Books, Inc, 1987.