Paleolithic hominid

Human ideas about the matter that makes up the world have developed in conjunction with our ability to transform and manipulate matter. We discovered the elements by trying to understand how we could do more with the material around us. These efforts go back to the very origin of human life. The manipulation of matter has been so important to human life that historians and archeologists have often identified different periods in history by the most advanced material a particular society could produce at a given time. Thus, we have the Paleolithic era, or Stone Age, followed by the Bronze Age and the Iron Age. The oldest stone tools, found in 1997 near the Gona River, in Ethiopia, by the researchers John W. K. Harris and Sileshi Semaw, date from 2.5 to 2.6 million years ago. Stone tools are the primary record of our hominid ancestors attempts to modify the environment. Tool use almost certainly predates this time, but objects made of other materials, such as wood, bone, or horn, have not survived the passing of the ages or cannot be clearly shown to have been tools. 

B.c.E. Stone tools Stone tools, used by Homo habilis and perhaps other hominids, first appear in the Lower Paleolithic age (Old Stone Age). 

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