(Left to right): Nicolas Hoizey/Unsplash; Graeme Churchard/Flickr/CC-BY 2.0; iStock.com/Jevtic

Top stories: Earth’s oldest life, a NASA mission to Titan, and whether growing up poor makes you wiser

The lower your social class, the ‘wiser’ you are, suggests new study

Society as a whole might be getting smarter, but we still don’t get along. Perhaps that’s because wisdom—the ability to take the perspectives of others into account and aim for compromise—reduces conflict, not intelligence. Now, a new study suggests such wisdom comes more naturally to those who grow up poor or working class.

NASA picks missions to Titan and a comet as finalists for billion-dollar mission

NASA selected the final candidates for its next billion-dollar robotic spacecraft Wednesday. The contenders would send a semiautonomous quad-copter to Saturn’s largest moon Titan or a spacecraft to the comet 67P/Churyumov-Gerasimenko on the next New Frontiers mission. The finalists have until January 2019 to refine their pitches to the agency, with a launch planned by 2025.

Bugs may be causing a common mold to produce a deadly toxin

The potentially fatal poison known as aflatoxin can stunt children’s growth and cause liver cancer. The toxin is produced by a common mold, Aspergillus flavus, that grows on crops. But only some of these molds produce the toxin. Now, researchers have shown that insects spur A. flavus to make aflatoxin, suggesting ways to keep it out of the world’s food supply.

Was trading by nomads crucial to the rise of cities?

Pastoralists have long been seen as likely architects of the long-distance trade networks that helped spur the rise of the world’s first civilization. But now, archaeologists are building a different picture, one that means nomads weren’t the natural conduits for trade. Instead, they assert herders mainly stuck close to and served the needs of specific urban areas, rather than migrating between far-flung cities.

Life may have originated on Earth 4 billion years ago, study of controversial fossils suggests

For 25 years, researchers have debated whether 3.5-billion-year-old microscopic squiggles encased in Australian rocks are evidence for the earliest life on Earth. Now, a comprehensive analysis of the microfossils suggests that these formations do indeed represent ancient microbes; ones potentially so complex that life on our planet must have originated some 500 million years earlier.