The Stone Age may have lasted 20,000 years longer in part of Africa than previously thought, recent archaeological finds revealed.
The new discoveries at sites in Senegal on the west coast of Africa, by researchers at the Max Planck Institute, are fueling a rethink of the passage of human evolution.
Previous discoveries suggested that about 30,000 years ago, people in Africa stopped using certain tools and methods – including simple points and scrapers – in favor of more complex and manufactured equipment, including spears and knives.
This distinction in equipment and a shift to a more artistic and regionally diverse approach to tools marks the transition from the Middle to the later Stone Age.
Archaeologists found that ancient West African inhabitants still used simple tools about 11,000 years ago – up to 20,000 years after falling out of favor elsewhere.
This refutes a long-standing theory that humanity evolved in a uniform way towards our modern lifestyles – and instead evolved at different speeds around the world.
The new discoveries at sites in Senegal on the west coast of Africa, by researchers at the Max Planck Institute, fuel a rethink of the passage of human evolution
The Stone Age is split into three periods – the Lower Stone Age before Homo sapiens, the Middle Stone Age in which the early Homo sapiens used simple tools such as points and scrapers – and the Late Stone Age in which craftsmanship began to grow.
Finds from the Middle Stone Age are most common in the African record between about 300,000 and 30,000 years ago, after which they largely disappear – although new research suggests this continued in some remote areas much later.
The exact transition varies from region to region, but the final stage of the later Stone Age – the Neolithic – takes place to the Bronze Age around 3,500 BC.
Archaeologists say their research supports the idea that – for most of humanity’s prehistory – groups of people were relatively isolated from one another.
The discovery comes as archaeologists are taking some of the first steps towards uncovering West Africa’s prehistoric past, which they say has been insufficiently studied compared to the eastern and southern reaches of the continent.
The lead author of a new study, Dr. Eleanor Scerri, said West Africa is a real frontier for human evolutionary studies – as almost nothing is known about prehistory.
“Almost everything we know about human origins is extrapolated from discoveries in small parts of eastern and southern Africa,” explains Scerri.
Her colleague, Dr. Khady Niang, from Cheikh Anta Diop University in Senegal, added: “These discoveries demonstrate the importance of exploring the entire African continent if we are to really get to grips with the deep human past.
“Before our work, the story from the rest of Africa suggested that well before 11,000 years ago, the last traces of the Middle Stone Age had long since disappeared.”
The team isn’t exactly sure why the inhabitants of the West African Stone Age took longer to adopt new tools, but speculate that this may be due to geographic isolation.
Other theories suggest it could also be due to less radical changes in the climate, which prevented people living there from finding new ways to adapt.
Archaeologists say their research supports the idea that – for most of humanity’s prehistory – groups of people were relatively isolated from one another. These drawings show some of the tools that were in use in West Africa 11,000 years ago and that were no longer used elsewhere
Dr. Niang said: “We can only be sure that this persistence is not just due to a lack of capacity to invest in the development of new technologies.
“These people were intelligent, they knew how to select good stones for their tool making and how to exploit the landscape in which they lived.”
The team said their findings, along with genetic discoveries showing a tremendous amount of diversity among people living on the continent, fit a newer view of human evolution that Stone Age groups separately lived and developed.
Dr. Niang said, “We’re not sure why, but beyond physical distance, there may also be some cultural boundaries. Perhaps the populations utilizing these different material cultures also lived in slightly different ecological niches. ‘
Team field hiking along the Gambia river, Senegal. The team isn’t exactly sure why the inhabitants of the West African Stone Age took longer to adopt new tools, but speculate that this is due to geographic isolation.
About 15,000 years ago, a great increase in humidity and forest growth in Central and West Africa linked several areas and provided corridors for groups to spread – marking the end of medieval tools.
Dr. Scerri added: ‘These findings do not fit a simple unilinear model of cultural change towards’ modernity’.
Embedded in radically different technological traditions, groups of hunter-gatherers occupied neighboring regions of Africa for thousands of years, sometimes sharing the same regions.
On the other hand, long isolated regions may have been important reservoirs of cultural and genetic diversity. This may have been a determining factor in the success of our species. ‘
The findings are published in the journal Scientific Reports.
WHAT DO WE KNOW ABOUT THE HISTORY OF THE STONE AGE?
The Stone Age is a period in human prehistory distinguished by the original development of stone tools that cover over 95 percent of human technological prehistory.
It begins with the earliest known use of stone tools by hominins, ancient ancestors of humans, during the Ancient Stone Age – about 3.3 million years ago.
Between about 400,000 and 200,000 years ago, the pace of innovation in stone technology began to accelerate very slightly, a period known as the Middle Stone Age.
At the beginning of this time, hand axes were made with exquisite craftsmanship. This eventually gave way to smaller, more diverse tool kits, with an emphasis on flake tools rather than larger core tools.
The Stone Age is a period in human prehistory distinguished by the original development of stone tools that cover over 95 percent of human technological prehistory. This image shows neolithic jadeite axes from the Toulouse museum
These toolkits are at least 285,000 years old in some parts of Africa and between 250,000 and 200,000 years in Europe and parts of West Asia. These toolkits last at least 50,000 to 28,000 years ago.
During the later Stone Age, the pace of innovation increased and the level of craftsmanship increased.
Groups of Homo sapiens experimented with different raw materials, including bone, ivory and antlers, as well as stone.
The period, between 50,000 and 39,000 years ago, is also associated with the arrival of modern human behavior in Africa.
Different groups sought their own specific cultural identity and adopted their own ways of making things.
Later Stone Age peoples and their technologies spread from Africa over the next thousands of years.