A New Picture of Amazon Populations Before Columbus Emerges

New study results suggest a lop-sided dispersal of ancient population groups in the Amazon Basin before Columbus.

The spread of indigenous pre-Columbian settlements in the Amazon Basin was not an even one, according to an analysis of the results of a recent study conducted by researchers from four research institutions.
The researchers, from the Florida Institute of Technology, the Smithsonian Institution, Wake Forest University and the University of Florida, led by Florida Tech's Crystal McMichael and Mark Bush, were attempting to determine the impact of human population in Amazonia before the Europeans arrived. Their hypothesis: If the Pre-Columbian Amazon was a landscape highly altered by humans, then most of the Amazon's current biodiversity could be the result of human impact. Because the Amazon Basin represents one of the planet's most significant areas of biodiversity, the question of how Amazonia was modified by humans in the past contributes to our understanding of rainforest ecology and informs us in our conservation efforts.
The team collected 247 soil cores from 55 locations in the central and western Amazon, sites like river banks and locations that archeological evidence had indicated were occupied by people. They also collected cores farther from the rivers, where historical and archaeological data were lacking. By using markers set in the cores, they were able to track the chronology of fire, vegetation and human alterations in the soil. No samples were collected form the eastern Amazon, as it has already been thoroughly studied.
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Crystal McMichael and Monica Zimmerman collect soil samples in the tropical rainforests of Peru. [Image courtesy of Crystal McMichael]

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Sampling site atop a river bluff overlooking the Madre de Dios River in the Peruvian Amazon. [Image courtesy of Benjamin McMichael]

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Their finds suggested that the early inhabitants of the central and western Amazon were concentrated near rivers and lakes, living in small groups, with some larger populations along some rivers. Even in the larger settlements, there was no evidence of high population and large-scale agriculture. Their impact on the rainforest was, for the most part, limited to the river banks, with little impact on the outlying forests. These results overturn the long-held notion that all of Amazonia was a highly populated area with large-scale agriculture before the Europeans arrived. At least in the central and western portions of the Amazon, people actually lived in smaller, mobile groups.
Said Bush: "There is strong evidence of large settlements in eastern Amazonia, but our data point to different cultural adaptations in the central and western Amazon, which left vast areas with very little human imprint." Adds McMichael: "The amazing biodiversity of the Amazon is not a byproduct of past human disturbance.....We also can't assume that these forests will be resilient to disturbance, because many have never been disturbed, or have only been lightly disturbed in the past. Certainly there is no parallel in western Amazonia for the scale of modern disturbance that accompanies industrial agriculture, road construction, and the synergies of those disturbances with climate change."
The detailed research report appears in the 15 June 2012 issue of Science. Science is published by AAAS, the nonprofit science society.
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Crystal McMichael teaches the value of paleoecological studies to local children in the village of Boca Amigos. [Image courtesy of Benjamin McMichael]

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 http://popular-archaeology.com/issue/june-2012/article/a-new-picture-of-amazon-populations-before-columbus-emerges