Thursday, September 26, 2013

Human occupation of Madagascar pushed back 2500 years

Past research concludes that human occupation of Madagascar was established around 500 C.E. in village communities by people of both Indonesian and East African heritage. Evidence for earlier visits is scattered and contentious, but recent archaeological excavations in northern Madagascar reveals a site containing microlithic stone technologies related to foraging for forest and coastal resources.

A flawed chronology

The evidence for human occupation prior to 500 C.E. does exist but is mainly circumstantial. Pollen and charcoal from fires suggest vegetation change linked to human activity around 2000 years ago, while cut-marks on animal bones push the date back to 400 BCE and possibly as far back as 2200 BCE. But until now there were few artefacts that could be used to establish the presence of humans on Madagascar.

The new study examined a rock shelter where the researchers – led by the late Robert E. Dewar of Yale University -  unearthed scores of flaked stone items made from materials brought from some distance away.

“Flaked stone items recovered primarily from washing and sorting are very small, a majority from a range of crypto-crystalline silicates, which we term ‘chert,’ and a minority of a volcanic glass which we term ‘obsidian’,” the authors write, noting that there are no known sources of obsidian in northern Madagascar. “Some of the fragments and flakes have pot-lid scars attributable to either deliberate heating, which improves flaking, or accidental burning.”

Using carbon dating techniques, the researchers were able to place an age on the stone tools of 3,500 to 4,400 years, corresponding to approximately 1460-2370 BCE. They also bear a striking resemblance to artefacts from this period found in Africa, the Middle East, and South-east Asia.

Intermittent occupation

The researchers say the results provide evidence of “intermittent occupation by small groups engaged in foraging” at the site.

This foraging occupation of one site effectively doubles and confirms the length of Madagascar’s known occupational history and thus the time during which people exploited its environments.

The rock shelter yielded a stratified assemblage with small flakes, microblades, and retouched crescentic and trapezoidal tools, probably projectile elements, made from cherts and obsidian, some brought more that 200 km.

The assemblage from the top layers of the site is well dated to 1050–1350 A.D. This was achieved using carbon dating and optically stimulated luminescence (OSL), as well as ceramic typology imported from the Near East and China.

Below this layer is a series of stratified assemblages with carbon dating and OSL indicating occupation from at least 2000 B.C.

Faunal remains reveal a foraging pattern of hunting parties active in Madagascar long before the arrival of farmers and herders and before many Late Holocene faunal extinctions.

A biodiversity hotspot

Madagascar split from India around 88 million years ago, allowing native plants and animals to evolve in relative isolation. Consequently, Madagascar became a biodiversity hotspot with over 90 percent of its wildlife found nowhere else on Earth. The island’s diverse ecosystems and unique wildlife are threatened by the encroachment of the rapidly growing human population.

The unique evidence collected by the researchers regarding extinction of mega fauna, such as gorilla sized Lemurs, shows that this occurred long after initial human arrival on the island and although later activities were clearly involved, the specific causes and pattern remain to be fully understood.

More generally, the view that Madagascar’s history can be sharply divided by the arrival of humans between an undisturbed Eden and anthropogenic disaster is no longer tenable.

The researchers conclude that more archaeological research is required to locate and excavate more of these forager sites and to understand “the chronology, origins, geographic spread, and environmental impacts of the human occupation of Madagascar”.
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References:

Past Horizons. 2013. “Human occupation of Madagascar pushed back 2500 years”. Past Horizons. Posted: August 14, 2013. Available online: http://www.pasthorizonspr.com/index.php/archives/08/2013/human-occupation-of-madagascar-pushed-back-2500-years

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