MYSTERY MAN

A trove of fossils found deep in a South African cave adds a baffling new branch to the human family tree. 

Conjured in clay and cast in silicone by paleoartist
John Gurche, Homo naledi is the newest addition to our genus.
MARK THIESSEN, NGM STAFF

BY JAMIE SHREEVE  •  PHOTOGRAPHS BY ROBERT CLARK (National Geographic - October 2015)

On September 13, 2013, two recreational cavers named Steven Tucker and Rick Hunter entered a dolomite cave system called Rising Star, some 30 miles northwest of Johannesburg. Rising Star has been a popular draw for cavers since the 1960s, and its filigree of channels and caverns is well mapped. Tucker and Hunter were hoping to find some less trodden passage.
In the back of their minds was another mission.
In the first half of the 20th century, this region produced so many fossils of our early ancestors that it  later became known as the Cradle of Humankind. Though the heyday of fossilhunting there was long past, the cavers knew that a scientist at the University of the Witwatersrand in Johannesburg was looking for bones. The odds of happening upon something were remote. But you never know.

Deep in the cave, Tucker and Hunter worked their way through a constriction called Superman’s
Crawl—because most people can fit through only by holding one arm tightly against the body and extending the other above the head, like the Man of Steel in flight. Crossing a large chamber, they climbed a jagged wall of rock called the Dragon’s Back. At the top they found themselves in a pretty
little cavity decorated with stalactites. Hunter got out his video camera, and to remove himself from the frame, Tucker eased himself into a fissure in the cave floor. His foot found a finger of rock, then another below it, then—empty space.

Dropping down, he found himself in a narrow, vertical chute, in some places less than eight inches  ide. He called to Hunter to follow him. Both men have hyper-slender frames, all ~on going~

Pigeons Make Flight Plans

Though their head-bobbing walk may be comical, pigeons in flight are no fools. They’re urban artful dodgers, threading their way among buildings and other obstacles. David Williams and his Harvard University colleagues studied the birds’ maneuvers to learn how they avoid collisions.
First Williams trained wild pigeons to fly through an empty corridor. Then he placed vertical poles at intervals in the corridor and videotaped the birds in the altered course. He expected them to use one evasive move consistently. Instead, the birds employed two moves, which researchers named: a “pause,” in which the wings stalled at the top of a stroke, and a “fold,” in which the wings were pulled back. Pausing was better for efficiently maintaining height, the study found, while folding
helped the birds fit through narrow gaps and remain stable in a collision. — Lindsay N. Smith

 source: National Geographic - October 2015