Evidence for use of stone tools first came from Olduvai Gorge in Tansania. These tools were found in the lowest levels dating to nearly 2.0 million years ago. In southern Ethiopia, stone tools dating to as early as 2.3 to 2.4 million years ago have been discovered. These are clearly not just rocks but true artifacts. Someone or something has modified them by percussion and use. There are different kinds of tools as well. The overall evidence suggests that between 2.3 and 2.5 million years ago hominids began to use stone materials as tools. In some cases, the individuals who made and used these tools came back to a single location and eventually deposited a concentration of these stone artifacts.
Who exactly was the first tool maker? That is a hard question to answer. Several different kinds of hominids were alive at the time when they first appear. The assumption has always been that it is a hominid that eventually belongs to the group "homo" that was the first tool maker. Clearly, it is Homo Erectus who becomes the first proficient more skilled tool maker with greater effort than anyone previous.
The first stone tools were probably made for two purposes: cutting something and pounding on something. Clearly you can cut and pound plant materials or use stone tools to dig for roots and tubers. However, it is far more likely that some hominids began to cut hides and meat and chop on bones to extract protein rich marrow. Of all of the tools made, the most important was probably the sharp flake that provided the edge by which one could cut even the toughest hides. It is probably unfortunate that the first stone tool tradition, the Oldowan Tool Tradition, is defined as a "core-chopper tradition". Cores are the means to detach flakes and it is these that were so vital to early hominid stone tool users.
The following two pictures are examples of finished core tools.
One of the earliest archaeological sites in the world has drawn a lot of attention regarding the role stone tools may have played in early hominid adaptations. This is the site FLK I in Olduvai Gorge. The site dates to roughtly 1.8 million years ago. It represents the repeated use of a single, rather confined locale near what would have been a small lake shore. As a result of the repeated use, a concentration of stone tools and animal bones accumulated. It is possible to look at microscopic traces of damage caused by stone tools or the teeth of carnivores on the fossilized animal bone found at FLK I. From this it is possible to determine that some of the bone at the site show signs that carnivores had chewed on the bones leaving their distinct tooth markings. Other signs point to the fact that stone tools cut into the bone as meat was cut off the bone and that bones, particularly long bones, were broken open using some sort of chopping tool.
What this evidence suggests is that these hominids who left us a glimpse of their life were probably scavenging. The implication was that they scavenged meat and bones from kills of lions, leopards and other carnivores. It seems that long bones were important sources of protein rich bone marrow as well. These hominids benefited from this way of life by tapping into a fatty-high energy food source. Along with collection of a variety of other foods - berries, roots and tubers, nuts, etc. these hominids probably developed a foraging strategy that enabled them to be successful. One of the keys to that success was their ability to locate kills and get to those kills quickly before other competing scavengers such as hyenas and vultures may have. This would have required development of running skills along with a certain level of cunning to know how to "out smart" other scavengers and anticipate the behavior of predators such as lions and leopards. Even knowing the behavior of a leopard who will frequently hide a kill in the limbs of tree may provide a meal. While this is not a great leap forward in terms of intelligence, it does signal the need to reinforce skills and capacities.
Clearly the diets of different hominids were different. Earlier hominids such as A. Africanus and A. Afarensis show an emphasis on a variety of soft plant foods. The robust australopithecines emphasized harded plant foods such as nuts and savanna seeds. To add meat to the diet mix would have been important. The African savanna provides a rich source of meat. In fact, there is a great abundance of meat on the African savanna. The trick is knowing how to get to it. This would include skills for getting to dead animals quickly and then getting to the meat and vital bone marrow. It is here that stone tools would have been the great advantange.
Technology and Transport -
Developing Strategies for Success
The story associated with the use of the first stone tools
and the subsequent adoption of stone tool technology as a means of adapting
to the African world is complex. It is probably intricately tied to changing
climates. Just as changing climatic conditions may have influenced the development
of bipedality, they seems to play a critical role in changing hominid behaviors
in the critical period around 2.5 million years ago. Rick Potts helps sort
this out in this reading from Humanity's Descent.
It was not until around 1.3 million years ago that more
extensive modification of cores took place and Homo erectus individuals
began to make hand axes which 
required
much more hand-eye control and skill. See the example to the right. The
hand axe would stay the primary element of the stone tool industry for nearly
a million years before more sophisticated tools would be developed. It is
a very versatile tools that could have been used in many ways. Oddly, enough
the hand axe is not found in China or Java while it is common throughout
Africa and Europe.
Reflect on the following: (The first segment has been
taken from Carl Sagan and Ann Druyan's Shadows of Forgotten Ancestors
while the second segment has been taken from Richard Leakey's new book Origin's
Reconsidered.)
Chimpanzee Tool Use (Pages 391-399)
Various Perspectives On Early Tool Use (Pages 187-199) and (Page 169)
Consider the implications of the following reading to
think about the implications of using stone tools, even those made by early
hominids over 1.0 million years ago. The following readings are taken from
Making Silent Stones Speak: Human Evolution and the Dawn of Technology
by Kathy D. Schick and Nicholas Toth (1993). This reading (pages 166-170)
should provide you with some sense of what archaeologists are learning about
not only the use of "simple" stone tools but also about the makers
and users of those tools.
(Pages 102-107) WHO WERE THE FIRST TOOL MAKERS 2.5 MYA?
(Pages 133-142) ARTIFACTS AS REFLECTIONS OF INTELLIGENCE
Keep in mind
that Chimpanzees do hunt....more on this.