What would life be like without thumbs? How would you hold your toothbrush? How would you turn a doorknob? How would you write with a pen? How would you hold your cellphone? How would you text?
Whoa. You can’t text without thumbs. You wouldn’t be able to tell all of your friends about your crazy weekend or how good that cereal was you ate for breakfast. Without your thumbs, you’re not connected to everyone – you’re lost in this technologically dependent, up-to-the-minute, interconnected world that we call the 21st century. Without your thumbs, the myriad, plebeian tasks that we so instinctually carry out every day become much more complicated and time consuming. Our thumbs are quite the advantageous trait; they make things so much easier. Holding your toothbrush, turning a doorknob, writing, and thankfully texting is an effortless, seemingly innate task. Don’t our thumbs deserve a “thumbs up?”
Now, if you were to ask a spider monkey (Ateles) this same question they would probably respond a bit differently. To them, and all of the other New World primates, thumbs would be an inconvenience – they would just get in the way. As a strictly arboreal species, spider monkeys, along with their fifty-three other New World counterparts, spend the majority of their day swinging from tree to tree in the dense tropical jungles of Mexico, Central, and South America.
Now you may be asking yourself, “Well, why do I care whether or not a spider monkey, or any monkey for that matter, has those two extra digits? They’re just monkeys!” Well, as a proud reader of a four hundred page textbook (with only a few pictures) all about monkeys, I can tell you that spider monkeys are absolutely fascinating creatures. The two extra digits on either hand were genetically unfavored when New World Monkeys diverged from Old World Monkeys about forty million years ago. They evolved without thumbs in order to improve their ability to climb and become masters of their arboreal environment. Without thumbs, they can easily move from one tree branch to the next, expertly avoiding the threats posed by jaguars, crocodiles, and other formidable predators. Without thumbs spider monkeys survive. They live without thumbs.
This is startling to think about because we can’t live without our thumbs. We can’t brush our teeth, we can’t open a door, we can’t write with a pen, we can’t hold our cellphone, and we can’t text. We can’t text! There is so much that we, as humans, cannot do without our thumbs. It’s unbelievable to think that a fellow animal can function without an appendage that is so crucial to our everyday life in all aspects social, physical, and intellectual.
So try it one day. Get some duct tape and tape your thumbs to your palms. See how challenging your life will be.