Wednesday, July 8, 2015

Teeth tell story about people buried at Harappa

Much of what modern researchers have gleaned about our common ancestors, particularly those from Egypt and Mesopotamia, comes from well-studied tombs and burial sites.

Discovering the narrative of peoples from the Greater Indus Valley — which comprises much of modern-day Pakistan and northwest India — is more challenging. The text of the Indus Valley Civilisation remains undeciphered, and known and excavated burial sites are rare. Recently, researchers have illuminated the lives of some individuals buried more than 4,000 years ago in those grave sites by providing a comparison of the dental enamel and chemical analyses of the water, fauna and rocks, using isotope ratios of lead and strontium.

The study is published in PLOS ONE (Open Access). In its heyday, Harappa held a population of 50,000, although the number of individuals represented by skeletal remains across the entire culture area totals in the hundreds.

Migrated to Harappa

When tooth enamel forms, it incorporates elements from the local environment  such as food, water and dust. When the researchers looked at remains from the ancient city of Harappa, located in what is known today as the Punjab Province of Pakistan, individuals’ early molars told a very different story than their later ones, meaning they hadn’t been born in the city where they were found.

The University of Florida research team was led by Benjamin Valentine, biological anthropologist John Krigbaum, and geological sciences professor George Kamenov, an isotope geologist.

“The idea of isotope analysis to determine the origin of individual migrants has been around for decades. But what people haven’t been doing is looking at the different tooth types, essentially, snapshots of residents during different times of individuals’ lives,” said Valentine. “We didn’t invent the method, but we threw the kitchen sink at it.” The researchers discovered that the people in the Harappa must have migrated there from the hinterlands. Said Krigbaum, “Previous work had thought the burial sites represented local, middle-class people. There was no notion that outsiders were welcomed and integrated by locals within the city. It’s not clear why certain young hinterland people were sent to the city.”

Past Horizons. 2015. “Teeth tell story about people buried at Harappa”. Past Horizons. Posted: A[pril 30, 2015. Available online:

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