It was conceived after a yogurt company in 2007 identified an unexpected defense mechanism that its bacteria use to fight off viruses. A birth announcement came in 2012, followed by crucial first steps in 2013 and a massive growth spurt last year. Now, it has matured into a molecular marvel, and much of the world—not just biologists—is taking notice of the genome-editing method CRISPR, Science’s 2015 Breakthrough of the Year.

CRISPR has appeared in Breakthrough sections twice before, in 2012 and 2013, each time as a runner-up in combination with other genome-editing techniques. But this is the year it broke away from the pack, revealing its true power in a series of spectacular achievements. Two striking examples—the creation of a long-sought “gene drive” that could eliminate pests or the diseases they carry, and the first deliberate editing of the DNA of human embryos—debuted to headlines and concern. Each announcement roiled the science policy world. The embryo work (done in China with nonviable embryos from a fertility clinic) even prompted an international summit this month to discuss human gene editing. The summit confronted a fraught—and newly plausible—prospect: altering human sperm, eggs, or early embryos to correct disease genes or offer “enhancements.” As a genetic counselor quipped during the discussion: “When we couldn’t do it, it was easy to say we shouldn’t.”

What sets CRISPR apart? Its competitors—designer proteins called zinc finger nucleases and TALENs—also precisely alter chosen DNA sequences, and several companies are already exploiting them for therapeutic purposes in clinical trials. But CRISPR has proven so easy and inexpensive that Dana Carroll of the University of Utah, Salt Lake City, who spearheaded the development of zinc finger nucleases, says it has brought about the “democratization of gene targeting.” Quoted in a recent issue of The New Yorker, bioethicist Hank Greely of Stanford University in Palo Alto, California, compares CRISPR to the Model T Ford: far from the first automobile, but the one whose simplicity of production, dependability, and affordability transformed society. “Any molecular biology lab that wants to do CRISPR can,” says Harvard University’s George Church, whose lab was one of the first to show that it efficiently edits human and other eukaryotic cells.

[…]

In short, it’s only slightly hyperbolic to say that if scientists can dream of a genetic manipulation, CRISPR can now make it happen. At one point during the human gene-editing summit, Charpentier described its capabilities as “mind-blowing.” It’s the simple truth. For better or worse, we all now live in CRISPR’s world.

A huge number of parasites can change the behavior of the organisms they infect. In some cases, parasites can even make their hosts display completely new behaviors. We understand very little about the mechanisms and pathways behind this interaction. To learn more, we investigated how a specific fungus changes the behavior of ants, by turning them into “zombie ants”. The infected zombies climb high and latch onto twigs just before they die, which helps the fungus to spread its spores a further distance.

Our results suggest that the fungus takes over the brain, secreting LSD-like compounds, expressing proteins that change serotonin and dopamine levels in the brain, and altering the ability to communicate with nearby ants. Our genome and transcriptome dataset, obtained using both field and lab techniques, allowed us for the first time to dive a bit deeper into the mechanisms used to regulate behavior. In the long run this work might even lead to discoveries related to human brain health.

The new research suggests that life existed prior to the massive bombardment of the inner solar system that formed the moon’s large craters 3.9 billion years ago.

“If all life on Earth died during this bombardment, which some scientists have argued, then life must have restarted quickly,” said Patrick Boehnke, a co-author of the research and a graduate student in Harrison’s laboratory.

Scientists had long believed the Earth was dry and desolate during that time period. Harrison’s research — including a 2008 study in Nature he co-authored with Craig Manning, a professor of geology and geochemistry at UCLA, and former UCLA graduate student Michelle Hopkins — is proving otherwise.

“The early Earth certainly wasn’t a hellish, dry, boiling planet; we see absolutely no evidence for that,” Harrison said. “The planet was probably much more like it is today than previously thought.”

The Colorado potato beetle is a voracious eater. The insect can chew through 10 square centimeters of leaf a day, and left unchecked it will strip a plant bare. But the beetles I was looking at were doomed. The plant they were feeding on—bright green and carefully netted in Monsanto’s labs outside St. Louis—had been doused with a spray of RNA.

The experiment took advantage of a mechanism called RNA interference. It’s a way to temporarily turn off the activity of any gene. In this case, the gene being shut down was one vital to the insect’s survival. “I am pretty sure 99 percent of them will be dead soon,” said Jodi Beattie, a Monsanto scientist who showed me her experiment.

To clone animals scientists take cells from one individual and insert them into an unfertilised donor egg which then develops into an embryo. In this case, the embryo was carried by a surrogate sheep, after a biopsy had been obtained from a mouflon. Domestic sheep oocytes were taken from abattoir ovaries, and the best embryos were transferred to the surrogate sheep.

Nasr-Esfahani said: “The cloning technique is very efficient in our view, and so far we have cloned a herd of goats. The last sheep that we cloned lived for over five years. This mouflon is healthy and 14 days have passed since its birth. We hope to donate the sheep to the city zoo where they can provide a suitable habitat for it.”

Then came a new wave of research, centering on careful trawls of the deep ocean with a new generation of nets in which the mesh was much finer. No matter how far the nets plunged, up came vast numbers of bristlemouths.

A team that trolled the Atlantic down to a depth of more than three miles reported in 2010 that the tiny fish “dominated the catches.”

Dr. Davison of the Farallon Institute, when he was a graduate student at the Scripps Institution of Oceanography, worked with colleagues there to plumb the Pacific off Southern California, doing so repeatedly from 2010 to 2012. Again, the little fish ruled.

Last year, oceanographers from Spain, Australia, Norway and Saudi Arabia reported on a research cruise that circumnavigated the globe to probe the life densities of the inky depths. It, too, reaffirmed the new wisdom, calling bristlemouths of the genus Cyclothone “the most abundant vertebrate on earth.”