I was at the zoo today and we were watching the gorillas dispose of a lot of things with their fine-hand coordination.
Besides peeling oranges, they could grip thin items like paper popcorn bags between thumb and forefinger and peel off strips.
(We tend to lump all “human” traits together, but this one seems to have had a jump on some of the others, like voice control and sustained bipedalism, which are also present to varying degrees among the primates.)
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Did you happen to notice Mr. ShowBiz that the great apes in question were confined in cages? Sheesh!
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Being confined to a cage causes opposable thumbs? 
Peace,
mangeorge
Great apes, Feh!
What about the dolphins?
Yup. All apes and monkeys gots the opposable thumbs. Prosimians I don’t know.
Cages - Primates in general and orangutans in particular are infamous for their talents at picking locks.
Other primates ? Sure: Tom DeLay.
Seems to be correct. Did a quick Google search and this is all I found that may be a reliable source…
http://biology.uindy.edu/Biol345/HUMAN%20STRATEGY/12hands.htm
In general, yes, all in the Order primates have a more or less usable thumb. This is not to say that all primate thumbs are actually opposable. The big notable exception is the Colobus monkey (Colobus guereza, et al) in which the thumb is vestigial or is entirely omitted. (colobus is Greek for ‘maimed’)
In the prosimian, the thumb is semi-opposable in most species, with a few wacky adaptations (witness the Tarsier) of the hand that prevents opposability.
In Family Hominidae opposability is the most pronounced, with fine motor control possible in some species. Tool use, (and in some cases manufacture) with the facility of the opposable digit has been noted in Pan troglodytes (Chimpanzee), Pan paniscus (Bonobo), Gorilla gorilla (Gorilla) and Homo sapiens (Brittney Spears).
While opposition of the thumb is very difficult in Pongo pygmaeus (Orang utan) due to the length and curve of the metacarpals, some individuals can accomplish it. As has been noted, the reputation as escape artists earned by orang utans is well deserved, with remarkably fine motor control possible using only the fingers.
See this site Primatology Source for more resources
Thank you, and Goodnight.
An interesting (to me, anyway) aside: While apes do have opposable thumbs, they do not possess ‘opposable’ fingers like Homo Sapiens. Try this:
Hold your hand out with your palm facing you. Curl your fingers straight down then put your thumb underneath the fingers. That’s an ape fist. Serviceable enough, but far from ideal. Now open your hand again. Bring your fingers around toward your extended thumb so that the pinky rests on the base of your thumb pad, the ring finger rests on the thumb pad, middle finger rests on base of thumb, and index finger rests on top of thumb. Homo Sapiens alone can accomplish this task. This grip is much more efficient for gripping most tools (and tennis raquets, golf clubs, etc. - that’s why a gorilla will never win at Wimbledon).
It’s a small diffence in hand structure that had a huge evolutionary impact. I love The Learning Channel.
Aye aye, sir.
Speaking of “gripping tools”, while a primates grasp may not be evolved enough to win Wimbledon, it’s most certainly evolved enough to manually stimulate their genitals or “spank the monkey” if you will, in full view of elementary school children. Trust me, I know.
Among New World monkeys, the Spider Monkeys (genus Ateles) and the Woolly Spider Monkey (Brachyteles) either lack thumbs entirely, or they are vestigial. Their big toes, on the other hand, are well developed and opposable.
Colibri:
You are quite right. My area of expertise is rather narrowly focused on Hominidae, but I do have some experience with Cercopithecidae. I tend to forget all about poor Cebidae. My apologies to any Cebid monkey I may have inadvertently offended. 
Would you explain that, please?
I don’t undertand your point.