What happened in the past when the climate changed?

Once again, humanity might be well served to take heed from a history lesson. When the climate changed, when crops failed and famine threatened, the peoples of ancient Asia responded. They moved. They started growing different crops. They created new trade networks and innovated their way to solutions in other ways too.

What happened in the past when the climate changed?
The effects of climate change are most pronounced in high latitude and high-altitude areas
[Credit: Jade d’Alpoim Guedes/UC San Diego]

So suggests new research by Jade d’Alpoim Guedes of the University of California San Diego and Kyle Bocinsky of the Crow Canyon Archaeological Center in Colorado, Washington State University and the University of Montana.

Their paper, published in the journal Science Advances, describes a computer model they developed that shows for the first time when and where in Asia staple crops would have thrived or fared poorly between 5,000 and 1,000 years ago.

When the climate cooled, people moved away or turned to pastoralism – herds can thrive in grassland where food grains can’t. And they turned to trade. These strategies eventually coalesced into the development of the Silk Road, d’Alpoim Guedes and Bocinsky argue. In some areas they also diversified the types of crops they planted.

With their new computer model, the researchers were able to examine in detail how changing climate transformed people’s ability to produce food in particular places, and that enabled them to get at the causes of cultural shift.

“There’s been a large body of literature in archaeology on past climates, but earlier studies were mostly only able to draw correlations between changes in climate and civilization,” said lead author d’Alpoim Guedes, an assistant professor in the Department of Anthropology and Scripps Institution of Oceanography at UC San Diego. “What we’re showing in this work is exactly how changes in temperature and precipitation, over space and time, would have actually impacted people – by affecting what they could and couldn’t grow.”

D’Alpoim Guedes is an archaeologist who specializes in paleoethnobotany – analyzing ancient plant remains – to understand how human subsistence strategies changed over time. Bocinsky is a computational archaeologist. The duo developed their model by combining contemporary weather station data from across Asia with a hemisphere-wide paleoclimate reconstruction to create a simulation across space and time of how temperature in Asia changed. They also added data on archaeological sites and the record of seeds found there.

One major transition in climate – global cooling at the time – happened around 3,700 to 3,000 years ago. And what is true now was true then: changing temperatures don’t affect all regions of the globe equally. The effects are most pronounced in high latitude and high-altitude areas, and d’Alpoim Guedes and Bocinsky show how dramatic the changes were, for example, in Mongolia and the Tibetan Plateau. There, around 3,500 years before the present, broomcorn and foxtail millet would have failed to come to harvest about half of the time. People had to abandon the crop in favor of more cold-tolerant ones like wheat and barley.

They also argue that cooling temperatures made it increasingly difficult to grow key grain crops across Northern China between AD 291 and 360, something that may have ended up playing a key role in the relocation of the Chinese capital to from Xi’an to what is now Nanjing, in the south of the country.

This was not a painless move – not like finding a better apartment across town. Historical records report on catastrophic harvests (read: famines). And there were major migrations of people, accompanied, the researchers say, by the myriad little conflicts these migrations often bring, as well as bloody struggles.

Climate change also stimulated the development of transportation infrastructure across Asia, the co-authors say, including the later Sui Dynasty’s decision to invest in a major capital public project and create China’s Grand Canal. The Grand Canal, now a UNESCO World Heritage Site, is the world’s longest and oldest canal, linking the Yellow and Yangtze rivers. It was a major facilitator for the movement of people and their trade goods.

D’Alpoim Guedes and Bocinsky’s paper in Science Advances [DOI: 10.1126/sciadv.aar4491] carries a positive title – “Climate change stimulated agricultural innovation and exchange across Asia” – but the co-authors also warn against a completely Pollyanna view.

“Crises are opportunities for culture change and innovation,” Bocinsky said. “But the speed and scale of our current climate change predicament are different.”

The impacts of warming going forward are going to be quicker and greater, and humanity has had 4000 years to adjust to a cooler world, d’Alpoim Guedes said. “With global warming these long-lasting patterns of adaptation will begin to change in ways that are unpredictable,” she said. “And there might not be the behavioral flexibility for this, given current politics around the world.”

Also mechanized, industrialized agriculture and global agricultural policy are pushing us toward mono-culture of crops, said d’Alpoim Guedes. We need to move in the opposite direction instead. “Studies like ours show that bet-hedging and investing in diversity have been our best bets for adapting to climate change,” she said. “That is what allowed us to adapt in past, and we need to be mindful of that for our future, too.”

For those wishing to reproduce the paper’s findings: The code is open source and any user of the free statistical software R can download the package the authors are making available and run the analysis themselves. Researchers can also extend d’Alpoim Guedes and Bocinsky’s findings by running analysis on other crops and other locations in different parts of the world. It is even possible, the co-authors say, to modify their code and then, potentially, to project for future crop failures.

Author: Inga Kiderra | Source: University of California – San Diego [October 31, 2018]

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Three stolen ancient Greek archaeological finds to be returned to Italy

A small vase for oils and ointments, a wine pitcher and a bowl for food are three archaeological finds from the Greek era that had been smuggled out of Italy and have been tracked down and will be brought back.

Three stolen ancient Greek archaeological finds to be returned to Italy
Credit: ANSA

The finds were recovered through collaboration between the cultural heritage section of the Carabinieri and the FBI and were handed over to Culture Minister Alberto Bonisoli on Wednesday in Washington.

Three stolen ancient Greek archaeological finds to be returned to Italy
Credit: ANSA

“On this occasion I want to announce that, in the next few months, a draft law of government initiative will be presented at the cabinet in collaboration with the foreign affairs ministry, the justice ministry and the ministry that I represent for the ratification of the Convention of Nicosia on crimes against cultural heritage,” Minister Bonisopli said at the ceremony in the Italian embassy in Washington.

Three stolen ancient Greek archaeological finds to be returned to Italy
Credit: ANSA

Over 15 years of collaboration between Italy and the US in working against the smuggling of archaeological finds was celebrated during the event.

The minister said that there would be stiffer penalties in the draft law.

Source: ANSA [October 31, 2018]

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Study finds most likely route of first humans into Australia

A new study from ANU indicates the most likely route the ancestors of Aboriginal people took to enter Australia for the first time tens of thousands of years ago.

Study finds most likely route of first humans into Australia
Gwion Gwion rock art site, Kimberley, WA [Credit: Peter Eve]

Co-lead researcher Shimona Kealy said these people probably travelled through Indonesia’s northern islands, into New Guinea and then Australia, which were part of a single continent between 50,000 and 70,000 years ago, when sea levels were 25-50 metres below the current level.

“We’ve created a treasure map of sorts with the likely route across land and water that these incredible people took to reach Australia,” said Ms Kealy, a Ph.D. scholar at the School of Culture, History and Language and an Associate Investigator at the ARC Centre of Excellence for Australian Biodiversity and Heritage at ANU.

“We’ve circled all of the islands that we want to explore further to find archaeological evidence to test if this is in fact the path that they took.

“Archaeologists have yet to explore most of Indonesia’s northern islands for human settlements predating the oldest sites found in Australia. These islands could hold the key to the mystery of how the first humans made it to Australia’s shores.”

The findings challenge a popular theory that these early adventurers travelled from Southeast Asia, through Indonesia and Timor and then across sea to reach Australia’s shores and land that is part of the Northern Territory today.

Study finds most likely route of first humans into Australia
Map of island Southeast Asia showing possible routes to Australia
[Credit: Shimona Kealy et al. 2018]

The study modelled the least-cost path from Southeast Asia to Australia, by considering factors such as difficulty to travel up slopes, visibility at sea, access to fresh water along the many potential pathways and the sophistication of maritime technology at the time.

Ms Kealy said the oldest dates for human occupation on the Australian-New Guinea continent (known as Sahul) represented the earliest, indirect evidence for sea faring by humans anywhere in the world.

“This study helps to tell the Australian story, particularly for Indigenous people, and acknowledges the bravery, innovation and maritime technologies and skills of these early modern humans,” Ms Kealy said.

The islands directly north and west of Sahul (known as Wallacea) were never connected to the mainland, requiring multiple successful water crossings east from mainland Southeast Asia (Sunda).

“These people hopped their way along these islands, probably looking for a place to live where they would have access to reliable food staples and other resources—the visibility between islands would have been very favourable in terms of enabling this adventurous spirit,” Ms Kealy said.

Co-lead researcher Professor Sue O’Connor from ANU said the proposed alternative route through Timor onto the northwest coast of Australia is now seen as less likely as a result of this study’s least-cost pathway modelling.

“The suggested route through Timor is also considered less likely given comprehensive archaeological evidence indicates the earliest human settlements in Timor are much younger than those found in Madjedbebe in Arnhem Land in the Northern Territory,” said Professor O’Connor, a researcher at the School of Culture, History and Language and a Chief Investigator at the ARC Centre of Excellence for Australian Biodiversity and Heritage at ANU.

The study is published in the Journal of Human Evolution.

Source: Australian National University [October 31, 2018]

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