Did You Know Pandas have “Thumbs”?

Did you know Pandas have thumbs, much like those of humans?  The front paws of a Giant Panda are distinctly different from other bears due to a special bone found in their wrists called the sesamoid bone. This bone crates their distinctive “sixth toe”, an opposable thumb, that is used for grasping bamboo.

This evolutionary adaptation inspired Stephen Jay Gould to write a book entitled The Panda’s Thumb: More Reflections in Natural History which contains an essay by the same name.  In this essay, Gould reflects,

“As a childhood fan of Andy Panda, and former owner of a stuffed toy won by some fluke when all the milk bottles actually tumbled at the county fair, I was delighted when the first fruits of our thaw with China went beyond ping-pong to the shipment of two pandas to the Washington zoo. I went and watched in appropriate awe. They yawned, stretched, and ambled a bit, but they spent nearly all their time feeding on their beloved bamboo. They sat upright and manipulated the stalks with their forepaws, shedding the leaves and consuming only the shoots.

I was amazed by their dexterity and wondered how the scion of a stock adapted for running could use its hands so  adroitly. They held the stalks of bamboo in their paws and stripped off the leaves by passing the stalks between an  apparently flexible thumb and the remaining fingers. This puzzled me.

Gould goes on to explore the adaptation further and concludes that, while it is no engineering marvel, “an enlarged wrist bone [is a] somewhat clumsy, but quite workable, solution” that “does its job and excites our imagination all the more because it builds on such improbable foundations.”

So the next time you are watching the Pandas on the cams in China – look a little closer – you might just be amazed.