(p. 30)

(p. 30)

(p. 30)

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(p. 30)

Dumb designs for sex: Evolutionary biology walks on the weird side (p. 16)

Speed dating offers scientists a peek at how romance actually blossoms (p. 22)

Finding signs of a lost beginning (p. 26)

One study finds tissue-specific methylation signatures in the genome; another a similarity between identical twins in DNA’s chemical tagging. (p. 5)

In past 50 years, apparently healthy forests have started losing trees faster, possibly because of climate change. (p. 8)

Satellite data show most of the continent is following worldwide trend. (p. 8)

A decline in fog and haze clears the air but also fuels 20 percent of the warming in Europe, a new study concludes. (p. 9)

The definitive discovery in Mars’ atmosphere of methane — often, but not always, a compound hinting at life — introduces the possibility of underground organisms. (p. 10)

Intel Science Talent Search finalists announced. (p. 11)

New field experiments indicate that wild capuchin monkeys choose the most effective stones for cracking nuts, suggesting deep evolutionary roots for the use of stone tools. (p. 12)

Thermal imaging and algorithms challenge famous estimate of extreme bat number. (p. 12)

A new brain-imaging study indicates that unusual neural activity linked to emotion, attention and conflict-resolution systems underlies a common psychiatric condition known as borderline personality disorder. (p. 13)

Study turns belief commonly held by video game industry, gamers, on its head. (p. 14)

Electrical measurements of sleeping newborn babies’ brains indicate that the 2- to 3-day-olds automatically detect a regular beat in rhythmic sequences, possibly reflecting an early capacity for learning music. (p. 14)

Review by Elizabeth Quill (p. 30)

Review by Sid Perkins (p. 30)

(p. 32)

Reader letters : February 14, 2009