Red Earth, White Earth, Green Earth, Black Earth
by Joseph L. Kirschvink
How a single mutant bacterium may have put Earth on the brink of extinction 2.3 billion years ago.
The Metathesis Waltz
by Douglas L. Smith
This year's Nobel Prize in Chemistry goes to a stately change-your-partners dance.
Molecular Switches for Cellular Sensors
by Christina Smolke
RNA molecules can do a lot more than just carry information.
Obituaries: Norman Horowitz