Cilia--the little hairs that propel a paramecium--flap spontaneously, and will synchronize their movements with neighboring cilia. But exactly why they do this has been hard to pinpoint because cilia are complicated structures; they're comprised of 650 different proteins, says Zvonimir Dogic, of Brandeis University. Reporting in Science
, Dogic and colleagues fabricated knockoffs with fewer components to see if they could figure out what drives the waving.
images, footage: Timothy Sanchez, David Welch, Daniela Nicastro, Zvonimir Dogic, AAAS