MI weekly selection #339
Supermassive black holes heading for collision found
A pair of supermassive black holes about 2.5 billion light-years away appear to be on a collision course with each other in a few more billion years, but astronomers say they can learn a lot about gravitational wave background noise now by observing them.
Ancient bird may have used extra-long toe to find food
The approximately 99 million-year-old remains of a tiny bird with an unusually long toe were found encased in amber in Myanmar in 2014. The new bird species, Elektorornis chenguangi, may have used the extra-long digit to dig into tree cracks for insects.
Zebrafish exhibit brain activity similar to REM sleep
The brain activity of slumbering zebrafish registers much like REM sleep experienced by mammals. Researchers say zebrafish ancestors evolved the basics of sleep about 450 million years ago, well before animals evolved, and that sleep may have first begun underwater.
Material has been leaking from Earth’s core
Researchers measuring element traces from the Earth’s deep mantle say material has been leaking from the core for 2.5 billion years. “Our study gives us a tracer that can be used to investigate core-mantle interaction and the change in the internal dynamics of our planet, and which can boost our understanding of how and when the magnetic field was turned on.”
Female-to-male switch in fish tracked
Researchers observed how bluehead wrasse fish change sex by observing females’ transitions to male once males were removed from a few Florida reef sites. They found that without males present, the females became stressed, aggressive and took on more male features, completing the sex-change process in as little as 20 days.