Ancient teeth reveal early human entry into rainforests
By Will Dunham
WASHINGTON (Reuters) - People adapted to living in tropical rainforests thousands of years earlier than previously known, according to scientists who found crucial evidence in 20,000-year-old fossilized human teeth discovered in Sri Lanka.
The researchers said there has been a debate over when our species first began living in rainforests, with some experts arguing such habitats may have been too daunting for early human hunter-gathers.
In a study published on Thursday in the journal Science, the scientists examined teeth from 26 people found at various archaeological sites in Sri Lanka for evidence of whether their diet consisted of rainforest plants and animals.
They obtained small tooth enamel samples using a diamond-tipped drill and analyzed them with an instrument called a mass spectrometer.
Almost all the teeth, including the oldest ones from about 20,000 years ago found at the Batadomba-lena rock-shelter in southwestern Sri Lanka, indicated a diet primarily of food from the rainforest.
"Humans have been manipulating and living within dynamic rainforest environments for at least 20,000 years and probably even longer," said University of Oxford archaeologist Patrick Roberts, who studies early human adaptations.
"The lifestyle, as we can see, was dedicated rainforest subsistence," Roberts added.
Scientists previously had not found direct evidence of human occupation of rainforest regions before about 10,000 years ago. Continued...