If Nietzsche Were a Narwhal: What Animal Intelligence Reveals About Human Stupidity

by Justin Gregg

This internal clock system is regulated by clock genes in our DNA. Once activated, these genes begin producing proteins—called PER proteins—that trickle into the cell during the night. Eventually, enough proteins will be produced that a threshold is reached and the clock genes stop making proteins. The PER proteins then slowly break apart until their numbers are so reduced that the clock genes turn back on and start making proteins again. This process takes almost exactly twenty-four hours—one full rotation of the Earth. This mechanism, called the transcription-translation feedback loop (TTFL), is found in the cells of most living things, from plants to bacteria to humans. It helps explain why all living things on the Earth—including animals that live in dark caves or at the bottom of the ocean where light does not penetrate—are nonetheless sensitive to the twenty-four-hour sun cycle. Jeffrey C. Hall, Michael Rosbash, and Michael W. Young were awarded the Nobel Prize in Medicine in 2017 for their discovery of clock genes in the 1980s.