Improved feet, legs may have spurred Homo's spread, experts say
WEDNESDAY, Sept. 19 (HealthDay News) -- When it came to spreading across the globe, humanity's early ancestors may literally have put their best foot forward.
So conclude paleontologists examining the partial skeletons of a group of four individuals who died in what is now the Republic of Georgia nearly 1.8 million years ago.
Their remains -- the earliest members of the Homo genus found to date outside of Africa -- are telling much about how key body changes propelled this group's spread around the planet.
"Their lower extremities are evolving faster than their brain and upper extremities, and that seems to be what's necessary for taking them out of Africa and on a long trip to other parts of the world," explained anthropologist Jeffrey Laitman, director of anatomy at the Mount Sinai School of Medicine, in New York City.
He was not involved with the research, which is published in the Sept. 20 issue of Nature.
According to the fossil record, mankind's ancestors arose from the first true bipeds, called australopiths, of which 3-million-year-old "Lucy" is an early member. They then went on to develop the larger brain capacity and more upright gait that characterizes the genus Homo, to which modern humans belong.
In Africa, the Homo genus included first Homo habilis and then the larger-brained Homo erectus. Both were increasingly comfortable walking upright on land over long distances.
In the early 1990s, scientists digging in Dmanisi, Republic of Georgia (between Turkey and Russia), came upon a remarkable find: The skull specimens of early Homo individuals dating to 1.77 million years ago. "When they were first described, it was really quite revolutionary to see material [like this] out of Africa," Laitman said.
But even though paleontologists can l
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