MI weekly selection #77
Orb-web spiders craft a unique disguise
An orb-web spider hides itself from predators by disguising itself as bird droppings, according to researchers. The spiders have a silver colored body that, when combined with their white disc-shaped webs, gives the illusion of bird excrement that may deter predatory wasps.
Ants are organized searchers who gain experience as they age
Scouting ants may seem to endlessly be searching for food, but there is a consistent pattern to their searches and they gain experience with each foray out of the nest, according to a study published in the Proceedings of the National Academy of Sciences. A team of German and Chinese researchers looked at previously published data seeking a mathematical pattern in addition to studying ants outside a lab setting in the presence of a nest.
Los Angeles Times / Science Now
Excitable neurons linked to depressive behavior in mice
A small group of neurons in the prefrontal cortex may be responsible for depressive behavior in mice. Scientists identified easily excitable neurons in depressed mice, and when they artificially excited those neurons in non-depressed mice, researchers were able to induce depression.
Study challenges idea that the oldest forms of bacterial life on Earth created tunnels in ancient rocks
Textures and tunnels found in 3.4 billion-year-old rocks were once thought to have been made by some of the oldest forms of bacterial life on Earth, but a new study suggests this may not be the case. The study theorizes that the tiny tunnels were created when volcanic rock cooled nearby, about 2.9 billion years ago.
Evolution of human brain came at expense of muscle strength
When it comes to evolution in humans, brain power trumps brute strength, according to a metabolic study. According to the study, the human brain evolved four times faster than the body in our early ancestors, while they evolved weaker muscles eight times faster than the rest of the body to fuel the greater metabolic needs of the brain.