MI weekly selection #534

Jupiter-like planets push Earth-sized planets aside

Jupiter-sized gas giant planets can cause chaos in young planetary systems, moving smaller planets out of their orbit and impacting the habitability of those planets. While Jupiter’s gravitational field acts as a shield for Earth, it would harm Earth’s climate if it were located in the middle of our habitable zone.

Full Story: Space

Sea stars’ bodies are just their head

Sea stars likely evolved to lose their torsos and tails, resulting in a body shape that is largely just a head. To investigate how sea stars differ from their bilateral relatives whose bodies are divided into a head, trunk and tail, researchers analyzed the genes of sea stars and discovered that the creatures lacked gene expression for torso and tail development but had genetic signatures relating to the head all over the body.

Full Story: CNN

Modern war in Europe started earlier than we thought

A new analysis of the remains of more than 300 Neolithic individuals in northern Spain indicates that large-scale, organized warfare in Europe may have begun 1,000 years earlier than archaeologists thought. Researchers found that the burial site, dating back around 5,000 years, shows evidence of intense skeletal injuries from conflict, particularly among men, and healed injuries that suggests the conflict lasted several months.

Full Story: Newsweek

Rats can imagine familiar environments

Researchers implanted electrodes into the hippocampal region of rats’ brains, placed the rats on a treadmill ball in an immersive virtual reality arena, presented an on-screen goal to run toward and gave the rats a treat when they reached the target. When researchers unhooked the treadmill in the VR environment, the rats mentally navigated through the environment, demonstrating that rats can imagine navigating familiar scenarios in much the same way humans do.

Full Story: STAT

Staying up all night creates a dopamine rush

Not getting enough sleep can temporarily relieve depression, according to a study of depression-induced mice that were given a good night’s rest or a sleepless night. Scientists found that the sleep-deprived mice showed a reversed depressive state, had higher dopamine activity in three brain regions — the prefrontal cortex, nucleus accumbens and hypothalamus — and formed new brain connections to maintain their elevated mood for several days.

Full Story: National Public Radio