Coming Onto the Land
The evolution of fish into walking land animals was one of the greatest chapters in the history of life. Now a remarkable fossil creature shows that all the real excitement happened underwater.
by Carl Zimmer
The Mars Model
Crashing comets and asteroids can do more than just kill off earthly dinosaurs. On other planets and moons, they can destroy entire atmospheres.
Magnetic Field Goal
A Penn State researcher has scored big with his maps of the human head's magnetic fields. These 3-D computer models could eliminate a vexing black hole at the center of some MRI scans.
Kim's Coils
Biochemist Peter Kim knew that proteins are a twisted lot. But only recently has he learned just how convoluted their path, and purpose, can be.
Kernel of Fear
How can just the smoke make a veteran relive all the horrors of combat in hallucinatory detail? The answer lies in the Amygdala, a tiny brain structure in which nerve pathways shackle innocent stimuli to memories of unbearable terror.