Evolution of stone tool culture (IMAGE) Pensoft Publishers Caption Chimpanzees make use of cobbles to break nuts, but they do not modify them. Homo habilis was one of the earliest hominin species that intentionally modified cobbles to manufacture the crude, Mode One choppers. Homo habilis was only able to break out large flakes from a cobble; its voluntary control of its mental template was quite crude. Homo erectus, on the other hand, was able to break off much smaller flakes and produce the fine, symmetrical, Mode Two hand axes. Therefore, Homo erectus was most likely capable of finer voluntary control of its mental template. Credit Andrey Vyshedskiy Usage Restrictions Credit must be given to the creator. License CC BY Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.