Nearly two-thirds of mutations in human cancers are attributable to random errors that occur naturally in healthy, dividing cells during DNA replication, researchers report in the 24 March issue of Science. Though mutations that cause human cancer have traditionally been thought to originate from heredity or environmental sources, these results — grounded in a novel mathematical model based on data from around the world — support a role for so-called "R" or random mutations in driving the disease.

AAAS staff members traveled to China in September to help promote the role of women in science during the meeting of the Academy of Sciences for the Developing World in Tianjin, to take part in a Hangzhou meeting on ethics in science, and to encourage the communication of peer-reviewed research.