Thaindian News

London, March 9 (IANS) Increased use of stone tools by our ancestors helped the human hand evolve unique characteristics.

Past research has borne out the existence of features in the bones and musculature of the human hand and wrist involved with gripping and manipulatory capabilities distinct from those of other apes.

These features suggest that at some point, since humans split from the last common ancestor of living apes, the human hand evolved away from features adapted for locomotion toward alternative functions, the Journal of Archaeological Science reports.

University of Kent anthropologists Stephen Lycett and Alastair Key have now shown that our ancestors’ hands may have been subject to natural selection as a result of using simple cutting tools, according to a Kent University statement.

In a series of experiments that used stone flakes similar to those known from Africa around 2.6 million years ago, they analysed whether variation in the hand size of individual tool users reflects differences that affect the efficiency of these simple tools to cut through a rope.

The results show that “biometric” variation did indeed result in a significant relationship with cutting efficiency in the experimental task.

Lycett said: “140 years ago, writing from his home at Down House in Kent, Darwin proposed that the use of stone tools may have influenced the evolution of human hands. Our research suggests that he was correct.”