Oakaie 1 (Myanmar) : The origins of farming

Etienne Bergès

Source - https://www.mmtimes.com/news/origins-myanmar-farming.html

S29, sampled individual. Photo: Supplied

New genetic evidence sheds light on how agriculture first reached the country.

For a nation where 70% of the labour force works in agriculture, we know surprisingly little about how farming came to Myanmar. It is thought that as far back as 3,500 years ago people were cultivating rice and domesticating pigs and chicken in the Irrawaddy valley. These acts may seem mundane today, but they laid the foundations for the complex cities, warring states, and kingdoms in present-day Myanmar, as was the case earlier in Egypt’s Nile basin or China’s Yellow River valley. In Myanmar, virtually everything remains to be discovered about who the inhabitants were – when and why they arrived, and how they mastered the landscape around them.

To shed some light on Myanmar’s origins, archaeologists are hard at work. Myanmar’s archaeological research seems at a turning point. A recent ancient DNA study of individuals living in ancient Myanmar suggests that the story is more complex than previously thought. Atthe step of a volcano in Sagaing division, to the east of Chadwin river, lies the prehistoric cemetery of Oakaie 1. There, dozens of individuals were buried between 3200 and 2700 years ago alongside pottery, beads and bracelets. Among them lie two adult women, dubbed“S28” and “S29” by the archaeologists who found them.

The pair were probably wrapped in a burial shroud and buried 3,000 years ago, after having lived in Myanmar’s late Neolithic era. Both were discovered in 2015 by the Franco-Myanmar Archaeological Cooperation Project, directed by U Aung Kyaw and Dr T.O Pryce. S28 and S29’sDNA have been analysed as part of the first ever whole genome study of prehistoric South East Asia, recently published in Science.

S28. Photo: Supplied

This research helps understand how people moved throughout the sub-continent’s prehistory. As South East Asia was populated by modern humans -put simply, our direct ancestors -over 70,000 years ago, these migrations have been rich and complex, particularly in Myanmar. “Finding sufficiently conserved ancient DNA in Oakaie I was a challenge,” explains Dr Pryce, “as prehistoric genetic material rarely preserves well in tropical environments”.

Ancient DNA technology is an exciting field in archaeology, which recovers and sequences old genetic material from old bones and teeth to elucidate clues about prehistoric human movements across the globe. But it is a tricky technique, and the DNA from S28 and S29’s ‘petrous bones’ -a particularly dense piece at the base of our skulls –were the only ones, amid fifty tested individuals, well preserved enough to take part in the research.

The results were surprising. They provided unique insights into how, when and where agriculture spread through Vietnam, Cambodia, Thailand and Myanmar. The general regional idea has been that between 4500 and 4000 years ago, the first South East Asian farmers took rice and millet down from what is now southern China into South East Asia, bringing with them Austro-Asiatic languages -for example, Khmer and Vietnamese. As they migrated outside of China into Myanmar and elsewhere, they mixed with local hunter-gatherer populations and began the region’s farming practices.

This study provides the first genetic evidence to support this idea. However, the ancient DNA of the two Myanmar samples differs from that of the studied individuals from Cambodia, Thailand and Vietnam. Instead says Dr Pryce, “They are closer to the DNA of current Sino-Tibetan speakers, which include many of today’s Myanmar people”. Sino-Tibetan includes Chinese languages as well as Jinghpaw, for example. This opens the possibility to a scenario where Myanmar’s first farming population was a different one than that of the rest of South East Asia as it “travelled via what is now south-western China, rather than the south-eastern Chinese passage responsible for Thailand’s and Vietnam’s Neolithicisation”.

Dr Pryce underlines that this important variation in Myanmar’s trajectory to agriculture provokes further exciting questions: where exactly did these farmers come into Myanmar, through the hilltops of Eastern Shan or along the river valley of the Irrawaddy? On the whole, Myanmar’s Neolithic remains uncharted territory.

Of course, decades of local and foreign archaeological work have proved wrong beyond doubt the perspective of colonial scholars, who placed the origins of civilization in Myanmar at 500 AD at the earliest. But understanding and studying Myanmar’s cultural heritage takes decades of work and trust building, insists Dr. Pryce, “We are now in a pivotal moment for Myanmar archaeology, as programs such as the Myanmar-Franco cooperation project collaborate to establish a solid cultural history for the country.”

These first results only make us want to know more about where Myanmar sits within South East Asia’s complex and rich prehistory – the country’s distant past is a space to watch.

The genetic study was written by Lipson et al. and published in Science in May 2018.