MI weekly selection #574

Storms’ mysterious gamma rays may trigger lightning

Surging flashes of gamma rays emanating from tropical thunderstorms may initiate lightning strikes, a group of physicists writes in a pair of papers in Nature that describe a never-before-seen type of gamma radiation as well as two rarely observed kinds. They write about data, collected from instruments on a spy plane converted for research by NASA, that shows radiation coming from storms in Central America and the Caribbean.

Full Story: Nature

Dinosaur-ending asteroid wasn’t the only one

A second asteroid slammed into Earth around the time a larger one destroyed the dinosaurs, researchers write in Nature Communications Earth & Environment, noting that they don’t know which collision happened first. The impact at the end of the Cretaceous period created the 450- to 500-meter Nadir crater, which is now off the coast of West Africa, and would have triggered at least an 800-meter tsunami.

Full Story: BBC

Human brains divide the day into chapters

Throughout the day, the human brain creates “chapters” of daily experiences based on personal priorities and attention, according to a study in Current Biology. Using audio narratives, researchers discovered that the brain organizes stories into events depending on what a person focuses on, rather than purely environmental changes.

Full Story: Neuroscience News

Genetic analysis traces origin of ant agriculture

Various ant species have evolved from a common ancestor that learned to farm fungi after Earth’s end-Cretaceous mass extinction, when fungi, unlike most plant life, were able to thrive amid abundant dead material and photosynthesis-blocking dust, according to findings in Science that analyze DNA from 276 ant species and 475 fungus species. Previous studies have demonstrated highly specific symbiotic relationships between a single ant species and a single fungus strain, and this paper suggests the origin of such cooperation.

Full Story: Ars Technica

Study maps 50M connections in fruit fly brain

An international research team has mapped more than 50 million connections in the brain of a fruit fly, a major step toward scientific understanding of brain functions behind such tasks as walking, grooming and seeing color. Published in Nature, a package of nine papers by researchers associated with the FlyWire Consortium represents the most detailed survey of an animal brain and could aid in the development of a similar map of the human brain.

Full Story: Nature