{description}Many organisms have circadian rhythms, internal clocks that are closely linked to the light-dark cycle of a day. Generally, if an organism’s internal clock is unsynchronized, it continues to live a normal life with no serious physical consequences. If these clocks seem so inconsequential, why has Mother Nature preserved them throughout evolutionary history? Recent research by Dr. Norman Ruby, a senior research scientist in Stanford’s Department of Biology, suggests that circadian rhythms are closely linked to the ability to learn new tasks. {/description}