Recent studies indicate that early human populations significantly transformed their environments, challenging previous assumptions.
Advanced Simulations Uncover Human Influence
A collaborative research effort, spearheaded by Aarhus University, utilized sophisticated computer models to analyze the interplay of climate, large fauna, natural fires, and human activities on European plant life during two warm historical periods. By correlating these models with extensive fossil pollen records, the team assessed the impact of each factor on vegetation.
The findings reveal a striking reality: both Neanderthals and later Mesolithic hunter-gatherers had a profound effect on vegetation patterns across Europe, predating the advent of agriculture.
"This research reshapes our understanding of the past," states Jens-Christian Svenning, a biology professor at Aarhus University. The project involved specialists from archaeology, geology, and ecology across The Netherlands, Denmark, France, and the UK.
"We discovered that climate change, large herbivores, and natural fires could not solely account for the pollen data. Including human activities, such as hunting and fire use, provided a more accurate representation," adds Svenning.
The results have been published in PLOS One.
Human Impact on Megafauna
The researchers focused on two significant warm periods in European history.
The first was the Last Interglacial period, approximately 125,000-116,000 years ago, when Neanderthals inhabited Europe. The second was the Early Holocene, from 12,000 to 8,000 years ago, following the last Ice Age, when Mesolithic hunter-gatherers thrived.
During the Last Interglacial, Europe was home to diverse megafauna, including elephants, rhinoceroses, bison, aurochs, horses, and deer. However, by the Mesolithic period, many of these large species had either disappeared or significantly declined, reflecting a broader trend of megafauna extinction following the global expansion of Homo sapiens.
A Fresh Perspective on Prehistoric Europe
"Our simulations indicate that Mesolithic hunter-gatherers could have influenced up to 47% of plant type distribution. Neanderthals had a smaller, yet measurable impact of around 6% on plant types and 14% on overall vegetation openness," explains Anastasia Nikulina.
The human influence manifested primarily through fire usage, which cleared trees and shrubs, and hunting large herbivores, a factor often underestimated.
"Neanderthals actively hunted massive creatures, including elephants weighing up to 13 tonnes. This hunting not only reduced herbivore numbers but also led to denser vegetation due to decreased grazing pressure. However, their limited population meant they did not eliminate these large species or their ecological roles, unlike later Homo sapiens," notes Svenning.
Nikulina and Svenning assert that these discoveries challenge the notion of Europe as an untouched wilderness prior to agricultural development.
"Neanderthals and Mesolithic hunter-gatherers were significant contributors to the ecosystems of Europe," emphasizes Svenning. "This study aligns with contemporary ethnographic research and archaeological findings, extending our understanding of human impact tens of thousands of years ago, before farming practices emerged," elaborates Nikulina.
Interdisciplinary Research and AI Simulations
Nikulina highlights the project's interdisciplinary nature, merging ecology, archaeology, and palynology (the study of pollen). The team developed intricate computer models to recreate ancient ecosystems.
"This is the first simulation to quantify the ways Neanderthals and Mesolithic hunter-gatherers may have influenced European landscapes. Our methodology combines a vast array of spatial data across centuries with AI optimization algorithms, allowing us to explore numerous scenarios and identify likely outcomes," states Nikulina.
Svenning emphasizes the clarity brought by the modeling.
"Our simulations demonstrate that climate change, large herbivores, and natural wildfires alone cannot explain the changes observed in ancient pollen data. To fully understand the historical vegetation, human impacts--both direct and indirect--must be considered. Even without fire, hunter-gatherers altered the landscape simply through their hunting activities," he explains.
Despite these advancements, gaps remain in our understanding of early human environmental influences.
Nikulina and Svenning suggest that similar simulations could be applied to other regions and eras. North and South America, as well as Australia, present exciting opportunities for comparison since they were not inhabited by earlier hominins before Homo sapiens, allowing for a clearer analysis of landscapes with and without human presence.
"While large-scale models provide a broad overview, detailed local studies are crucial for enhancing our comprehension of prehistoric human landscape shaping," concludes Svenning.
