Top 25 stories of 2013, from microbes to meteorites

Last year it was easy to choose a story to lead our annual Top 25 list. The discovery of the Higgs boson was a watershed moment, ending a decades-long quest by thousands of physicists to fully describe the subatomic realm.

This year, nothing so momentous came to pass. But science isn’t just about dramatic announcements and tremendous technical feats. Anyone who reads Science News regularly appreciates that great new insights often arise from countless little bits and pieces of new knowledge. This year, careful readers may have noticed a steady accumulation of revelations about the bacterial communities that call the human body home. It has long been known that those microbes are essential to processes like extracting nutrients from food and fighting off their less benign brethren. But this year a growing body of research demonstrated that bacteria engage their hosts so vigorously that in some situations, scientists are left wondering which party is the tail and