Living things must deal with a universe that is both regular and ever-changing: No day exactly mirrors the last, yet the sun and moon still appear at their appointed hours.
Cells contain their own seeming chaos, with countless molecules cooperating to produce subtle responses and behaviors. And in recent decades, a great deal of focus has specifically centered on the periodic patterns that underlie many cellular processes.
Oscillations — such as a pendulum’s swing or a ball’s bouncing on the end of a spring — are among the simplest and most common phenomena in physics, but researchers have come to appreciate their ubiquity in the biological world, too. Concentrations of molecules rise and fall, genes alternate between on and off, and circadian clocks keep time almost as well as human-made machinery. Together, these biochemical fluctuations are crucial for a blizzard of biological needs: timing daily activities, orchestrating cell division and movement, even mapping out parts of an embryo as it grows. Cells would be unable to function without them.
[Synthetic biologist Michael Elowitz of Caltech discusses the importance of oscillations in cells, and how they are inspiring scientists to create cells with new functions. (Credit: Hunnimedia for Knowable Magazine)]
