Sunday, March 1, 2015

Unknown Human Lineage

Just thought this was cool we don't usually talk about the evolution of our own species 

22,000-Year-Old Skull Could Represent Unknown Lineage Of Humans

February 27, 2015 | by Lisa Winter
photo credit: copyright President and Fellows of Harvard College
Homo sapiens first appeared on the planet 200,000 years ago, but the earliest members of our species looked quite different from what we look like today. In fact, there has been a great deal of diverse skull morphologies throughout our tenure on Earth due to various changes in brain size, diet, and other cultural factors. A new paper published in theProceedings of the National Academy of Sciences describes a 20,000-year-old human skull fragment from Kenya that doesn’t closely match any human skulls from other areas during the same time. This discovery highlights the incredible amount of human diversity that occurred in the Late Pleistocene. 
The skull was originally discovered at the Lukenya Hill site in Kenya, where it has been sitting in storage at a local museum since the 1970s. As the body of knowledge in the field of paleoarcheology has grown immensely since the decades that followed since the skull fragment’s discovery, an international team of researchers decided to take another look and see if there was any new insights to be had. Upon re-examination, they noticed a few oddities about the skull. While it was indeed Homo sapiens, it did not match what had been found during the same time period in distant locations, such as Asia and Europe. 
"It looks like nothing else, and so it shows that original diversity that we've since lost," lead author Christian Tryon from Harvard’s Peabody Museum told Tia Ghose of Live Science. "It's probably an extinct lineage.”
Along with the skull, the site also contained other items that the researchers believe give clues about the evolution of human culture, such as 46,000-year-old ostrich eggs that are believed to have been used to make decorative beads, providing clues about early ornamentation. 
The researchers believe the immense diversity of Homo sapiens skull morphology during this time period correlates to prevailing culture. Increased brain volume that permits the intelligence to develop tools or indulge in ornamentation changed the size of the brain casing, while differences in diet and food preparation altered the shape of the mouth. 
Discerning human culture within the last 12,000 years has been much easier, as the species shifted toward domesticated agriculture, larger communities, and burying the dead—which tremendously aided the fossilization process. Going back farther than this, however, becomes tricky. Without burial to protect against the elements, there are fewer complete skeletons and fewer artifacts that have stood the test of time in order to provide context for day-to-day life. Certain clues, such as the decorative eggshell beads and skull shape of the individuals who used them, paint a much richer picture of what happened during these earlier years.

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