(left to right): T. APPENZELLER/SCIENCE; Tom Bouyer/Expedition 5300; ISTOCK.COM/ANTAGAIN

Top stories: Mountain-moving climate change, an oxygen-starved city, and rats playing hide-and-seek

Global warming has made iconic Andean peak unrecognizable

When famed naturalist Alexander von Humboldt scaled Chimborazo, a 6268-meter-high volcano in Ecuador, the many distinct ecosystems and climate zones led him to a realization that changed how we view the structure of nature: Humboldt proposed that climate is an organizing principle of life, shaping the distinct communities of plants and animals found at different altitudes and latitudes. Now, global warming is quickly reshuffling those montane climates—and few peaks record the impact of human-driven climate change more vividly than Chimborazo itself.

Hypoxia city

At 5100 meters above sea level, a gold-mining boomtown in southeastern Peru called La Rinconada is the world’s highest human settlement. The city suffers from systemic problems such as mercury contamination, violence, and alcohol abuse, but one issue in particular has drawn researchers to the settlement for years: the city’s thin air. Nearly one in four residents suffers from chronic mountain sickness, a condition caused by a long-term lack of oxygen. Earlier this year, a team of scientists traveled to La Rinconada to learn more about the disease—and to search for a treatment.

Lab rats play hide-and-seek for the fun of it, new study shows

Every child knows that a proper game of hide-and-seek must follow a strict set of rules. Players can’t switch from being the “seeker” to the “hider” midway through the game, for example, and hiders have to stay put until they’re found. Now, scientists have discovered that lab rats can rapidly learn the rules to hide-and-seek and, so far as they can tell, love playing the game with people.

The secret of static electricity? It’s shocking

Rub a balloon on your head, and your hair will stand on end. Nearly everyone has done it, or at least seen it. But even though static electricity was first observed by the ancient Greeks, scientists still don’t know why rubbing certain materials together generates an electrical charge. Now, they may have the answer.

Suspect surfaces in the mysterious case of the underwater research station that vanished

Divers in the Baltic Sea remain on the hunt for an unusual sunken treasure: an 800-kilogram, €300,000 underwater scientific observatory that went missing several weeks ago. The internet has been flooded with speculative explanations—scrap metal thieves or a Russian sub, perhaps—but a few clues have surfaced to suggest a more prosaic culprit: A boat, possibly fishing illegally, somehow hooked the facility and dragged it away.