Extinction of Animal Species Following Early Human Invasion of South America

When the first prehistoric humans arrived in South America at the end of the Ice Age, they encountered a remarkable land filled with water and vegetation, inhabited by various strange animals ranging from giant sloths to badgers the size of cars. However, these early humans acted like 'invasive species,' rapidly increasing their population and ruthlessly exploiting the natural resources of the area. It took a long time for human population growth to stabilize after the establishment of permanent settlements and the beginning of sustainable agriculture and animal husbandry. According to Reuters, these findings have been published in the scientific journal 'Nature,' providing the most comprehensive view of South America, the last continent inhabited by humans. Researchers identified two distinct phases of population formation in this region: the first phase from about 14,000 years ago to 5,500 years ago, when the human population reached about 300,000; and the second phase from about 5,500 years ago to 2,000 years ago, when the population grew to about 1 million. Elizabeth Hadley, a professor at Stanford University, states, 'Humans are just like other invasive species. If our resources run out, we will decline. The results of this research indicate that humans can rapidly consume resources even in vast geographical areas like continents.' Researchers reconstructed the history of human population growth in South America using radiocarbon dating methods and data from 1,147 archaeological sites. This method allows for determining the age of all organic materials (substances derived from living organisms). Our ancestors first appeared in Africa about 200,000 years ago, then migrated to Europe and Asia, and finally entered the Americas about 15,000 to 20,000 years ago. The first phase of population formation in South America led to the extinction of many large animals, including proboscideans, saber-toothed cats, sloths, badgers, and large flightless birds. Amy Goldberg, an anthropologist at Stanford University, notes, 'During this period, the human population experienced cycles of increase and decrease due to the use of plant and animal resources.' Some people, especially in specific areas of the Andes, began domesticating animals and cultivating crops such as squash and peppers. However, most remained nomadic. According to Goldberg, about 5,000 years ago, people settled in sustainable communities, and a rapid population growth phase began that tripled the population of the Americas. She adds that they found that not only sustainable food resources but also large settlements allowed humans to conquer their surroundings and grow unchecked. Most of them lived in present-day Peru, Ecuador, and northern Chile, but a small yet significant number also settled in Patagonia.