MI weekly selection #66
Favorable weather gave rise to Genghis Khan
Tree-ring scientists have linked favorable weather patterns with the rise of Genghis Khan and the Mongol empire, according a report in the Proceedings of the National Academy of Sciences, putting a new spin on the history of the Mongols. The steppes had an unusual 15-year period of rain and mild weather during that period. “Where it’s arid, unusual moisture creates unusual plant productivity, and that translates into horsepower — literally. Genghis was able ride that wave,” said study co-author Amy Hessl, a tree-ring scientist at West Virginia University.
Gut bacteria boosts immune cell production
California Institute of Technology researchers have found that gut bacteria are vital in the development of white blood cells, which help fight infections, according to a study published in the journal Cell Host & Microbe. Scientists compared the white blood cell counts of healthy mice with normal gut bacteria and mice without gut bacteria, and found that the latter had few immune cells and stemlike cells capable of becoming immune cells. Infusions of gut bacteria increased white cell counts in germ-free mice.
Ancient whale fossil indicates echolocation began earlier than thought
A study of the fossil remains of a new whale species shows that it used echolocation to navigate the oceans 28 million years ago, according to a report in Nature. The skull of the Cotylocara macei has air pockets like those found in modern-day dolphins and porpoises that helped them send sound beams. The find suggests that the beginning of echolocation in the evolution of whales began about 32 million years ago, much earlier than previously thought. “It suggests echolocation evolved very, very early in the history of the group that involved toothed whales,” said anatomist Jonathan Geisler of the New York Institute of Technology, co-author of the study.
Rainbow hints at new information about Venus
A rainbow phenomenon called a “glory” has been seen in the atmosphere of Venus, the first time such a rainbow has been spotted on another planet, researchers say, and the rare occurrence could offer clues about that planet. Sunlight strained through cloud droplets produces rainbows and glories, which are circular and can only be seen from above. “This could be the so-called unknown absorber that people had been trying to identify for years. We cannot say for sure, but we can say that this is one more piece of the puzzle for the whole thing,” said Wojciech Markiewicz, a scientist at the Max Planck Institute for Solar System Research.
Piece of Earth’s interior ‘ocean’ found in diamond
A tiny crystal found in a diamond has confirmed predictions about a giant store of water deep in the Earth’s mantle. The rock is the first direct evidence to back up theoretical models made over 20 years ago, and suggests the vast underground ‘reservoir’ – 500km below Earth’s surface – could hold more water than all the world’s oceans combined.