Okay this post is actually about people. I saw the following a news article. There is enough here for you to google and find the original article.
October 07, 2013 According to a news release from the RIKEN Brain Science Institute, early hominids evolved finger dexterity and tool use ability before the evolution of bipedal locomotion. RIKEN researchers contend that their findings identify a solution to a long-lasting puzzle in human evolution.
The point being that a lot of smart people believe that our human hand dexterity relates more to the reason that a raccoon also has an opposable thumb than the reason that monkeys do. The idea is that we evolved for a significant period of time around/in a shallow body of water and searched for food in murky areas like a raccoon. The opposable thumb is more from a need to grab quickly than to grab a just a branch.
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