Feature

Behavior

Time-Reversed Shadows from Future Passed

Leakey’s New Skull Changes Our Pedigree and Lengthens Our Past

Lasker Honors 18 for Cancer Chemotherapy

Air Quality: Decision on Nondegradation Upheld

Back Matter

Astronomy

Water Quality: Giving States Their Guidelines

This Is Going to Hurt You More than It Hurts Me

Front Matter

Gobble, Gobble, Gobble, My Mother’s Not a Turkey

Earth Sciences