Scientists are refining carbon dating techniques to make the archaeological timeline more precise. (p. 344)

Reversing earlier advice, health authorities now say that babies of HIV-positive mothers in poor countries have a better chance of avoiding infection if they feed only on breast milk that's not supplemented with other food. (p. 187)

Orangutans try to communicate by gesturing when they think they're being misunderstood, much as people do when playing charades. (p. 158)

Some nectar-feeding bats metabolize sugars as rapidly as hummingbirds do. (p. 141)

The events of 9/11 put new urgency into efforts to design buildings able to withstand the structural damage that fire can cause. (p. 122)

A Central American beetle changes color in a novel way, using its body fluid to control the reflectivity of its shell. (p. 99)

Chemicals used to disperse marine oil spills are more harmful to coral than the oil itself. (p. 67)