Like many life sciences, chronobiology is a field that has transitioned from the organismal level, to anatomical dissection, to molecular analysis. The emerging biochemical view of circadian and other biological rhythms is revealing how organisms assess and respond to oscillating (back and forth) environmental cues that result from the Earth's movements. "All such biological clocks are adaptations to life on a rotating world," says William Schwartz, a professor of neurology at the University of Massachusetts Medical School in Worcester.
Early work in the field focused on documenting the existence of biological rhythms, and then on identifying parts of the nervous system that could be, or house, a clock mechanism. Today, researchers are pinpointing genes whose protein products constitute the workings of biological clocks.
EVOLUTIONARY CLUE: Michael Young says biological clock mechanisms may help to determine species origin.
Researchers have long...