Mimicking how spiders make their complex array of silks could usher in a tapestry of new materials, and other animals or plants could be designed to be the producers (p. 24)

Scientists trace a new path behind the maddening, unrelenting, screaming desire to scratch (p. 16)

Physicists are stirred by claims that the sun may change what’s unchangeable—the rate of radioactive decay (p. 20)

Chemical biomarkers in ancient Australian rocks, once thought to be the oldest known evidence of complex life on Earth, may have infiltrated long after the sediments were laid down, new analyses suggest. (p. 5)

Using genetic engineering and chemical manipulation, scientists erased the memory of a stressful experience from a mouse’s brain. (p. 8)

A drug used against leukemia can ease disability in early-stage multiple sclerosis patients over a three-year span. (p. 9)

A vaccine against rotavirus shows potent protection against the diarrhea-causing pathogen in its first year of widespread use. (p. 9)

Malaria is thwarting frontline drugs called artemisinins in Cambodia. (p. 9)

A fungus called Cryptococcus gattii that causes meningitis is slowly making its way down the North American West Coast. (p. 9)

Excavations in southern Jordan have incited controversy about whether a copper-producing society existed there 3,000 years ago, and whether it was controlled by Israeli kings described in the Old Testament. (p. 10)

A widely used agricultural weed killer teams up with fertilizer to render frogs especially vulnerable to debilitating parasites. (p. 12)

Epsilon Eridani hosts an inner asteroid belt and planet arranged like those in the solar system. (p. 13)

Expectant mothers, including spiders, need to eat well. For Mediterranean tarantulas, a male suitor tastes just fine. (p. 14)

Tracked bar-tailed godwits break previous nonstop flight record for birds. (p. 14)

A large study offers clues to the genetics behind lung cancer. (p. 15)

Some harmful strains of E. coli might rely on something sweet to do harm. (p. 15)