KENT, England, March 10 (UPI) -- U.K. researchers say they've confirmed the evolution of unique features in the human hand was influenced by increased tool use in our ancestors.
Scientists say a number of features found in the bones and muscles of the human hand and wrist that provide specific gripping and manipulatory capabilities are different from those of other extant great apes, LiveScience.com reported Thursday.
One theory has held that after humans split from the last common ancestor of living apes, the human hand evolved away from features suitable for locomotion toward alternative functions.
Anthropologists at the University of Kent have found the hands of our ancestors may have been evolved by natural selection as a result of using simple cutting tools.
Stephen Lycett and Alastair Key used stone flakes similar to those known from Africa around 2.6 million years ago and analyzed whether variation in the hand size of individual tool users reflects differences that affect the cutting efficiency of these simple tools.
Their results show "biometric" variation did indeed result in a significant relationship with cutting efficiency in the experimental tasks.
Charles Darwin had it right, the researchers 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," Lycett said.
"Our research suggests that he was correct. From a very early stage in our evolution, the cultural behavior of our ancestors was influencing biological evolution in specific ways," he said.
