色情视频

鈥淚f we only look at what has changed over the past 50 years, it doesn鈥檛 help us understand how we have come to the ecosystems today.鈥�

When an international group of anthropologists and paleontologists gathered for a workshop in Australia to share global datasets for the first time, they discovered island extinctions that had happened across the world were not due to human arrivals in the Pleistocene Epoch.

The resulting research paper was published this month in . The researchers examined archaeological and paleontological records of islands around the world inhabited by humans and their ancestors over the past 2.6 million years. They found humans weren鈥檛 always destructive agents and their arrival often had minimal impacts on biodiversity loss.

鈥淏ased on classic cases of island extinction from the more recent past, we expected that mass extinction should shortly follow island colonization,鈥� said associate professor Julien Louys with the Australian Research Centre for Human Evolution. 鈥淗owever, when we examined the data, there were very few cases where this could be demonstrated.

鈥淓ven in cases where there was a close link between human arrival and island extinctions, these could not be disentangled from records of environmental change brought about by global climatic events and changing sea levels,鈥� Louys said.

色情视频 professor of anthropology Todd Braje took part in the 2017 research workshop led by Louys and senior researcher professor Sue O鈥機onnor of the Australian National University.

鈥淗istorically, the story has been that when humans arrived they were these destructive predators who immediately altered island environments,鈥� Braje said. 鈥淚t鈥榮 been one of the justifications for linking humans in the Americas with the extinction of megafauna like mammoths and mastodons. In the study data, we found much the opposite.鈥�

Braje has been doing research for the past twenty years on California鈥檚 Channel Islands, which were colonized by humans at the end of the Pleistocene.

During the Pleistocene, the human condition was much different than today.

This study asks important questions that lay the groundwork for environmental change in the future. Climate change and overhunting as a cause of island extinctions have been hotly debated over the past 40 years, however a review of historical data suggests there could be a complex combination of issues leading to extinction.

Imperiled ecosystems

Island ecosystems are some of the most at-risk in the world today and understanding the past impacts of humans on these environments is critical to safeguarding them for the future.

鈥淏y studying the cases where people lived on islands for thousands of years without tipping these fragile ecosystems off balance, we might gain valuable insights into how they can be better managed today,鈥� Louys said.

Understanding why and how climate, ecosystems and biota have shifted over time helps anthropologists think about how to address the damage done, Braje explained.

鈥淚f we only look at what has changed over the past 50 years, it doesn鈥檛 help us understand how we have come to the ecosystems today,鈥� he said. 鈥淲hy do the landscapes and seascapes look like they do today? We can understand the long-term, entangled human environmental change that is creating the present. By understanding the deep history, we can decide what we want these places to look like in the future. We have a choice about effective resource management and how to build sustainable systems.鈥�

鈥淟essons learned here offer a message of hope, that humans are not always to be blamed for all the destruction. We can find ways to live sustainably in a fragile ecosystem.鈥�

The research was funded by the Australian Research Council Laureate Fellowship for O鈥機onnor and the Wenner-Gren Foundation.