How Did the Invention of Stone Tools Over 2.6 Million Years Ago Transform Early Human Life? — Here’s What Researchers Found Out

Several million years ago, there was evidence recorded that shows humans were not yet apex predators. They were vulnerable to bigger, stronger, and faster predators. It is also hard for them to hunt animals on their own, and they often rely on scavenging resources from other species’ hunt carcasses.

Some of the earliest species of human lineage, such as Australopithecus, did not even eat a lot of meat yet and had a plant-rich diet instead. However, over 2 million years ago, something changed, and humans started to make stone sharper until it could cut tougher materials. Soon, it affected almost every aspect of their lives. But how exactly did the invention of stone tools transform them? Let’s dive deep into our ancestral past in this article.

Changing Diet — Eating Meat and Tough Foods

First, have you heard of the saying that you are what you eat? This actually has some evolutionary basis, too. Earlier human lineages, before they began incorporating meat in their diet, had a different anatomy. Their jaws and teeth were powerful and large. It was used to be able to bite through tough plant materials like tubers or underground roots.

They also had smaller brains, as it is a metabolically expensive organ that needs calorie-dense food in order to grow and be maintained. So, for early humans that were built for a different lifestyle, the invention of stone tools, even just the most basic ones, changed them drastically but gradually over time.

Around 2.6 million years ago, early humans developed what is now called the Oldowan stone tool industry. It refers to a set of different stone tools that were made by chipping at a stone using another stone to make it sharper, or to be more adequate for their purpose. The evidences were found in sites like Gona, Ethiopia, and Olduvai Gorge in Tanzania.

One of the biggest effects of these stone tools was allowing early humans to access and eat foods that were once impossible for them to get. Using sharpened stone tools, they were able to cut through meat and add more nutrition to their diet. They were also able to reach the bone marrow after scraping the meat off the carcasses. The nuts that were hard to open can now be pounded by hammerstones, and hard roots can now be cut instead of just biting into them.

The ability to access more food sources made early humans more adaptable, as having mixed diets means that if one source of food became scarce, they could still obtain the other one and survive. With more options and more flexibility, means a higher chance of survival, especially in the harsh environment of Earth millions of years ago.

Read more: Smithsonian Magazine

Better Efficiency, Energy, and Survival

Oldest Known Stone Tools Discovered: 3.3 Million Years Old | National Geographic

Stone tools not only provided humans with better access to more food sources around them. After hundreds of thousands more years, they were able to refine these stone tools slowly and add them to their daily lives. Every day tasks like gathering resources became more efficient with the help of stone tools, saving a lot of energy that could be allotted to a different work instead.

That extra energy could go to thinking, planning, and moving instead. Archaeologists also found that early humans would often bring these tools with them, showing that they knew that only specific stones could be made into these tools and that they had planned and strategized, and did not just randomly make stone tools.

Then, around a few million years later, these stone tools allowed them to expand their diet even further by learning how to hunt much more efficiently. Before this timeline, there was a theory that early humans hunted by using persistence, where they would track and chase their prey under the scorching heat of the sun until these creatures collapsed or could not run and fight any longer.

But with the invention of more advanced stone tools like stone-tipped spears, this process became much better, as they could now strategize to ambush and immediately deliver a critical blow to their prey.

This meant that their survival did not only rely on gathering plant food sources, or scavenging meat leftovers of other carnivorous animals. Instead, with stone tools, they were able to learn to hunt much more successfully.

Brain, Social Life, Sharing, and Culture

Stone tools like the Oldowan industry tools did not just change the diets of humans; they also could’ve directly and indirectly affected the social structures of early hominins. First, when it allowed them to obtain more resources, it probably also meant the group could support a higher number of people.

This leads us to the social brain and brain growth hypothesis, which posits that the intelligence and brain size of early humans increased over the last 2 million years. One of the primary reasons was the change in diets, which was influenced heavily by stone tools, allowing humans to access more food by successfully cutting and scraping more meat off carcasses, and even getting the bone marrow. The increase in nutrition that the body gets means it now has enough fuel, which was a prerequisite for human brain growth.

But one of the theories also included the increasing number of individuals in an earlier human group. As hominins formed a larger population, their brain had to adapt to recognize allies, enemies, social structure, and navigate the complexity of human cooperation. These factors may have placed a higher demand and pressure on the brain to grow and cognitive abilities to increase.

The growth of the brain is not just because of any one cause, but comprises a multitude of reasons. However, the inventions of stone tools may have provided the necessary prerequisites for it, such as access to a better diet, the ability to sustain a higher population, and the evolutionary pressures that come with it.

Moreover, the better the cognition of the brain, the higher the intelligence humans can achieve, eventually giving rise to culture and the passing of knowledge. Additionally, early humans may have also learned to share their tools or extra food sources from much efficient scavenging using the stone tools, which increases cooperation and trust in the group, making every individual’s chances of survival higher.

Read more: Yale News

Tool Use and Human Evolution

Human Evolution: Oldest Evidence Of Stone Tool Use

The invention and use of stone tools did not just change what humans ate, but soon, it also influenced who they became. The once larger and more powerful jaws and teeth changed as there was a reduction in selective pressure because stone tools allowed them to cut and crush the hard food materials.

The demand for toolmaking, which is a skill that increases their chances of survival and reproduction, may also have played a role in the development of our hands. The precision grips and specialized fine motor control that we now have today could have been developed in the past because of the need for our hands to make tools and use them in our daily lives.

Additionally, because of stone tools, humans became much better generalists and survivalists. Because of the adaptability it provided, such as access to mixed diets, protection from predators, and influence in the development of human anatomy, earlier hominins were able to occupy new ecological niches. This included new forestry areas, hard cave terrains, open grasslands, and woodlands. As our ancestors spread around the globe, the stone tools also improved together with them.

Author's Final Thoughts

The evolution of humans was accompanied by our development of stone tools. The first industry of toolmaking was the Oldowan about 2.6 million years ago, but some research finds even older stone tools at about 3.3 million years ago. However, the point is, this is a key trait that marked the turning point of human history, but it was not instantaneous. Its development was gradual, and it took countless iterations and refinements before it made us the apex species on the planet.

The first stone tools allowed us to access new food sources that were previously unattainable. They also helped us save more energy for moving and thinking, they encourage social cooperation, and they shaped human anatomy over time. What began as a simple rock hitting another rock to make it pointier became the foundation for brain growth, cultural development, technological innovations, and the way of humans.

Read next: Why Did So Many Other Hominins Vanish in Europe Around 1.1 Million Years Ago? — Here’s What Scholars Discovered

References & Further Reading

Semaw, S., et al. (1997). 2.5-million-year-old stone tools from Gona, Ethiopia. Nature. https://doi.org/10.1038/385333a0

Harmand, S., et al. (2015). 3.3-million-year-old stone tools from Lomekwi 3, West Turkana, Kenya. Nature. https://doi.org/10.1038/nature14464

Plummer, T. W., et al. (2023). Expanded geographic distribution and dietary strategies of the earliest Oldowan hominins. Science. https://doi.org/10.1126/science.abo7452

de Heinzelin, J., et al. (1999). Environment and behavior of 2.5-million-year-old Bouri hominids. Science. https://doi.org/10.1126/science.284.5414.625

de la Torre, I. (2016). The origins of the Acheulean: past and present perspectives on a major transition in human evolution. Philosophical Transactions of the Royal Society B. https://doi.org/10.1098/rstb.2015.0245

McPherron, S. P., et al. (2010). Evidence for stone-tool-assisted consumption of animal tissues before 3.39 million years ago at Dikika, Ethiopia. Nature. https://doi.org/10.1038/nature09248