Under California’s Proposition 65 law, products containing chemicals that may cause cancer, birth defects or reproductive toxicity must carry a warning label at their point of sale. Among such products: pricy balsamic and red-wine vinegars that contain lead. At least some California groceries apparently have taken a conservative approach and post labels suggesting all such vinegars are dangerously tainted. Although they aren't.

Scientists have traced the reappearance of cotton pests in west-central Texas to a tropical storm.

DNA of infamous Phytophthora microbe reveals big, quick-changing zones, possibly the key to the pathogen’s vexing adaptability

Nitrous oxide has become the leading threat to the future integrity of stratospheric ozone, scientists report.

Until a century or so ago, nobody had any idea that there even was such a thing as quantum physics. But while humans operated for millennia in quantum darkness, it seems that plants, bacteria and birds may have been in the know all along. Quantum effects, human researchers have only recently discovered, may explain how the first steps of photosynthesis convert light to chemical energy with such high efficiency. Other studies suggest that quantum tricks may enable migratory birds to navigate using Earth’s magnetic field lines. Through studies like these, scientists are beginning to un... (p. 26)

Variation underlies the Callery pear tree’s transformation . (p. 5)