Other animals with opposable thumbs include gorillas, chimpanzees, orangutans, and other variants of apes; certain frogs, koalas, pandas, possums and opossums, and many birds have an opposable digit of some sort. Many dinosaurs had opposable digits as well. Granted, most of these are primates, as are we.
Hand evolution The development of an opposable thumb that enables humans to grip and manipulate objects is widely believed to give us an evolutionary edge. But new research finds that human hands are more primitive than those of our closest primate ancestors chimpanzees. The study, published in the the journal Nature Communicationsfound that human hand proportions have changed little from those of the last common ancestor of chimps and humans, while the hands of chimps and orangutans have evolved quite a bit.
Share animal photographs or incredible animal facts. Did You Know? The human hand with the opposable thumb, as we see it today, evolved around two million years ago.
The fact that humans have opposable thumbs, and other primates such as chimpanzees do not, suggests that our hands are more evolved to cope with skills such as using tools. The team came to their conclusion by studying the hands of modern primates and the remains of early apes and human ancestors. Specifically, they examined the thumb to finger length, which in humans and gorillas is characterized by a relatively long thumb compared to the four fingers, resulting in opposable thumbs. In chimps, their hands are much longer and narrower, and they do not have opposable thumbs.
By Chris Baraniuk. An opposable thumb is supposed to be a sign of a sophisticated species. But apes called bonobos make little use of their thumbs when they hang from tree branches — even though we use ours to keep a tight grip.
Part of Hall of Human Origins. As the grasping hand evolved, claws disappeared. Today, most primates instead have flat fingernails and larger fingertip pads, which help them to hold on.
Today, the controversy is a tad less intense, yet rages on in some circles. We humans are primates, along with a lot of other apes and monkeys. There are certain characteristics that define us as primates.
Humans have an opposable thumb, meaning that they are able to simultaneously flex, abduct and medially rotate the thumb pollex so as to bring its tip into opposition with the tips of any of the other digits. Humans share pollical opposability with most other catarrhines old world monkeys and apes. These differences, especially with respect to relative thumb length, make it difficult for non-human primates to employ tip-to-tip precision grips when manipulating small objects such that small objects must generally be pressed by the thumb against the lateral side of the index finger. The greater mobility of the human thumb, and our enhanced ability to manipulate small objects with thumb tip-to-finger tip precision grips, likely evolved for finer manipulative abilities in the context of increased dependence on, and elaboration of, technology.
There are numerous primate species in the world, and they all have thumbs. But the actions and movements these thumbs allow varies as greatly as the species themselves. From grasping, climbing, hanging, peeling, throwing, fishing and even creating tools, having a thumb opens a whole new world of dexterity.
With three exceptions, all primates have retained five digits on hand and foot. The exceptions are the spider monkeys and the so-called woolly spider monkey of South America and the colobus monkeys of Africa, which have lost or reduced the thumb. This appears to be an adaptation for locomotion, the rationale for which is not fully understood at present.