Circadian rhythms from flies to human

In this era of jet travel, our body 'remembers' the previous time zone, such that when we travel, our sleep-wake pattern, mental alertness, eating habits and many other physiological processes temporarily suffer the consequences of time displacement until we adjust to the new time zone. Although the existence of a circadian clock in humans had been postulated for decades, an understanding of the molecular mechanisms has required the full complement of research tools. To gain initial insights into circadian mechanisms, researchers turned to genetically tractable model organisms such as Drosophila.