A remarkable new method to prepare single strands of ancient DNA and view their genomes topped the list of this year's runners-up for Breakthrough of the Year, along with important discoveries into transcription activator–like effector nucleases, neutrino physics, Majorana fermions, the production of eggs cells from stem cells, and brain-machine interfaces. Other notable advances involve the Encyclopedia of DNA Elements, the Mars Curiosity rover, and the use of x-ray lasers to determine protein structure.

In 2013, Science's editors will be watching single-cell sequencing, the European Space Agency's Planck satellite, the Human Connectome Project, expeditions to study subglacial Antarctic waters, cancer immunotherapy, and basic plant research.

Two controversial studies that showed how to make the H5N1 avian influenza virus transmissible among mammals have left scientists wondering which kinds of studies are worth the risk and how potentially dangerous results should be reviewed and safely communicated to the public and public health experts.