What significant change is associated with the use of stone tools in early hominids?

The use of stone tools by early hominids is closely associated with significant changes in dentition and brain size. The evolution of tool use required these early hominids to adapt to new dietary practices. As they began using tools to process food more effectively, especially in terms of meat consumption and the processing of tough plant materials, there was a corresponding shift in dietary needs that influenced the shape and size of their teeth. This adaptation is reflected in the reduction of the size of teeth over time, as less robust structures were necessary for processing food.

Furthermore, increased reliance on tool-making and use also suggests a shift in cognitive abilities, which is often linked to changes in brain size. The complex thought processes required for planning, creating, and using tools would have fostered neurological development, leading to the expansion of brain size over generations. This combination of changes in dentition—favoring smaller teeth suited for a varied diet—and increased brain size reflects the significant evolutionary impact of tool use in early hominids.