The Great London [Search results for South East Asia] 

The transition from hunter-gatherer to sedentary farming 10,000 years ago occurred in multiple neighbouring but genetically distinct populations according to research by an international team including UCL.

“It had been widely assumed that these first farmers were from a single, genetically homogeneous population. However, we’ve found that there were deep genetic differences in these early farming populations, indicating very distinct ancestries,” said corresponding author Dr Garrett Hellenthal, UCL Genetics.

The study, published today in >Science and funded by Wellcome and Royal Society, examined ancient DNA from some of the world’s first farmers from the Zagros region of Iran and found it to be very different from the genomes of early farmers from the Aegean and Europe. The team identified similarities between the Neolithic farmer’s DNA and that of living people from southern Asia, including from Afghanistan, Pakistan, Iran, and Iranian Zoroastrians in particular.

“We know that farming technologies, including various domestic plants and animals, arose across the Fertile Crescent, with no particular centre” added co-author Professor Mark Thomas, UCL Genetics, Evolution & Environment.

“But to find that this region was made up of highly genetically distinct farming populations was something of a surprise. We estimated that they separated some 46 to 77,000 years ago, so they would almost certainly have looked different, and spoken different languages. It seems like we should be talking of a federal origin of farming.”

The switch from mobile hunting and gathering to sedentary farming first occurred around 10,000 years ago in south-western Asia and was one of the most important behavioural transitions since humans first evolved in Africa some 200,000 years ago. It led to profound changes in society, including greater population densities, new diseases, poorer health, social inequality, urban living, and ultimately, the rise of ancient civilizations.

Animals and plants were first domesticated across a region stretching north from modern-day Israel, Palestine and Lebanon to Syria and eastern Turkey, then east into, northern Iraq and north-western Iran, and south into Mesopotamia; a region known as the Fertile Crescent.

“Such was the impact of farming on our species that archaeologists have debated for more than 100 years how it originated and how it was spread into neighbouring regions such as Europe, North Africa and southern Asia,” said co-author Professor Stephen Shennan, UCL Institute of Archaeology.

“We’ve shown for the first time that different populations in different parts of the Fertile Crescent were coming up with similar solutions to finding a successful way of life in the new conditions created by the end of the last Ice Age.”

By looking at how ancient and living people share long sections of DNA, the team showed that early farming populations were highly genetically structured, and that some of that structure was preserved as farming, and farmers, spread into neighbouring regions; Europe to the west and southern Asia to the east.

“Early farmers from across Europe, and to some extent modern-day Europeans, can trace their DNA to early farmers living in the Aegean, whereas people living in Afghanistan, Pakistan, Iran and India share considerably more long chunks of DNA with early farmers in Iran. This genetic legacy of early farmers persists, although of course our genetic make-up subsequently has been reshaped by many millennia of other population movements and intermixing of various groups,” concluded Dr Hellenthal.

Source: University College London [July 14, 2016]

A new and more dangerous phase of impacts on the world's remaining tropical forests is emerging, threatening to simplify the world's most diverse ecosystem including mass species loss, according to new UCL-led research published today in Science.

The impact of humans on these areas has been increasing for millennia and today more than three-quarters of the world's remaining tropical forests have been degraded by human actions.

The scientists identified three prior phases of expanding impacts, the first when hunter-gatherers moved into tropical forests and the second following the emergence of tropical agriculture, some 6,000 years ago. Under both, the overall health of tropical forests was maintained.

Today, we live in the third phase, marked by much greater impacts, with distant decision-makers directing how land is used, including permanent intensive agriculture, often for soybeans or palm oil, frontier industrial logging for timber export, cross-continental species invasions, and early climate change impacts. The scientists term this phase the era of 'Global Integration', affecting even the most remote areas.

Lead author, tropical forest expert Dr Simon Lewis (UCL Geography and University of Leeds) said: "Earth has lost 100 million hectares of tropical forest over the last 30 years, mostly to agricultural developments. Few people think about how intertwined with tropical forests we all are. Many foodstuffs include palm oil which comes from once pristine Asian tropical forest, while remaining intact forests are buffering the rate of climate change by absorbing about a billion tonnes of carbon each year."

Current trends look set to intensify without major policy changes, as global food demand is projected to double, over 25 million kilometres of road are predicted to be built by 2050, and climate change intensifies, ushering in a new phase of human dominance of tropical forests.

Dr Lewis added: "I fear a global simplification of the world's most complex forests. Deforestation, logging and road building all create fragmented patches of forest. However, as the climate rapidly changes the plants and animals living in the rainforest will need to move to continue to live within their ecological tolerances. How will they move? This is a recipe for the mass extinction of tropical forest species this century.

"What is needed are unbroken areas of forest that link today's core tropical regions with forest areas about 4 degrees cooler, so as temperatures rise and rainfall patterns change species have a better chance of surviving rapid 21st century climate change. We need to bring conservation in line with the reality of climate change."

The authors note that while deforestation and degradation continue, more optimistically, logged forest retains many environmental benefits, and marginal agricultural lands are being abandoned, which can return back to forest.

Dr David Edwards (University of Sheffield), co-author of the study, said: "Much biodiversity still remains in selectively logged forests, and can recover in secondary forests that grow on abandoned farmland. There is abundant potential to incorporate these forests into global plans to make tropical biodiversity climate change ready.

"Despite their value for biodiversity, logged-over and old secondary forests are frequently threatened by conversion to species-poor agricultural plantations. We urgently need to protect these human-impacted forests, especially in regions such as Southeast Asia where almost nowhere is left undegraded."

A suite of policy measures can help tropical forests survive, including giving forest dwellers formal collective legal rights over their land, which previous studies have shown is one of the best ways of preserving forests. A study of 292 protected areas in Amazonia showed that indigenous reserves were the most effective at avoiding deforestation in high pressure areas.

Most of the financial benefits of logging and plantation agriculture, such as palm oil, flow out of the forests. Ensuring local people have collective long-term rights over their lands would mean that benefits flowing from forest lands accrue to local people. This can provide the beginnings of programs of 'development without destruction', tackling poverty while maintaining forests. This, the authors argue, provides human rights and conservation win-wins.

Dr Lewis added: "With long-term certainty of tenure people can plan, maintaining forests while investing in improving agricultural productivity without expanding into forested lands. Forest dwellers won't be perfect managers of forests, but they won't look for a quick profit and then move on, as big businesses often do.

"This is a pivotal year for the global environment. There are some good signs for the world's tropical forests, with the UN New York Declaration on Forests agreeing to not only halt deforestation, but also restore 150 million hectares of forest. However, there are ominous signs too, with the palm oil industry having driven the world's highest deforestation rates in South East Asia now gearing up to repeat this process across Africa.

"The Paris climate change talks in December are doubly important for forests and forest communities. The levels of emission cuts will be a critical factor in determining how many tropical forest plants and animals go extinct over the coming decades and centuries. The agreements on reducing deforestation, including durable finance, will be pivotal. The final test will be whether some funds for adaptation will include land-use planning to retain forest connectivity as the climate rapidly changes."

Source: University College London [August 24, 2015]

The leopard (Panthera pardus), one of the world's most iconic big cats, has lost as much as 75 percent of its historic range, according to a paper >published in the scientific journal PeerJ. Conducted by partners including the National Geographic Society's Big Cats Initiative, international conservation charities the Zoological Society of London (ZSL) and Panthera and the International Union for Conservation of Nature (IUCN) Cat Specialist Group, this study represents the first known attempt to produce a comprehensive analysis of leopards' status across their entire range and all nine subspecies.

The research found that leopards historically occupied a vast range of approximately 35 million square kilometers (13.5 million square miles) throughout Africa, the Middle East and Asia. Today, however, they are restricted to approximately 8.5 million square kilometers (3.3 million square miles).

To obtain their findings, the scientists spent three years reviewing more than 1,300 sources on the leopard's historic and current range. The results appear to confirm conservationists' suspicions that, while the entire species is not yet as threatened as some other big cats, leopards are facing a multitude of growing threats in the wild, and three subspecies have already been almost completely eradicated.

Lead author Andrew Jacobson, of ZSL's Institute of Zoology, University College London and the National Geographic Society's Big Cats Initiative, stated: "The leopard is a famously elusive animal, which is likely why it has taken so long to recognize its global decline. This study represents the first of its kind to assess the status of the leopard across the globe and all nine subspecies. Our results challenge the conventional assumption in many areas that leopards remain relatively abundant and not seriously threatened."

In addition, the research found that while African leopards face considerable threats, particularly in North and West Africa, leopards have also almost completely disappeared from several regions across Asia, including much of the Arabian Peninsula and vast areas of former range in China and Southeast Asia. The amount of habitat in each of these regions is plummeting, having declined by nearly 98 percent.

"Leopards' secretive nature, coupled with the occasional, brazen appearance of individual animals within megacities like Mumbai and Johannesburg, perpetuates the misconception that these big cats continue to thrive in the wild—when actually our study underlies the fact that they are increasingly threatened," said Luke Dollar, co-author and program director of the National Geographic Society's Big Cats Initiative.

Philipp Henschel, co-author and Lion Program survey coordinator for Panthera, stated: "A severe blind spot has existed in the conservation of the leopard. In just the last 12 months, Panthera has discovered the status of the leopard in Southeast Asia is as perilous as the highly endangered tiger." Henschel continued: "The international conservation community must double down in support of initiatives — protecting the species. Our next steps in this very moment will determine the leopard's fate."

Co-author Peter Gerngross, with the Vienna, Austria-based mapping firm BIOGEOMAPS, added: "We began by creating the most detailed reconstruction of the leopard's historic range to date. This allowed us to compare detailed knowledge on its current distribution with where the leopard used to be and thereby calculate the most accurate estimates of range loss. This research represents a major advancement for leopard science and conservation."

Leopards are capable of surviving in human-dominated landscapes provided they have sufficient cover, access to wild prey and tolerance from local people. In many areas, however, habitat is converted to farmland and native herbivores are replaced with livestock for growing human populations. This habitat loss, prey decline, conflict with livestock owners, illegal trade in leopard skins and parts and legal trophy hunting are all factors contributing to leopard decline.

Complicating conservation efforts for the leopard, Jacobson noted: "Our work underscores the pressing need to focus more research on the less studied subspecies, three of which have been the subject of fewer than five published papers during the last 15 years. Of these subspecies, one—the Javan leopard (P. p. melas)—is currently classified as critically endangered by the IUCN, while another—the Sri Lankan leopard (P. p. kotiya)—is classified as endangered, highlighting the urgent need to understand what can be done to arrest these worrying declines."

Despite this troubling picture, some areas of the world inspire hope. Even with historic declines in the Caucasus Mountains and the Russian Far East/Northeast China, leopard populations in these areas appear to have stabilized and may even be rebounding with significant conservation investment through the establishment of protected areas and increased anti-poaching measures.

"Leopards have a broad diet and are remarkably adaptable," said Joseph Lemeris Jr., a National Geographic Society's Big Cats Initiative researcher and paper co-author. "Sometimes the elimination of active persecution by government or local communities is enough to jumpstart leopard recovery. However, with many populations ranging across international boundaries, political cooperation is critical."

Source: PeerJ [May 03, 2016]