Draft Revised and Re done

Ricky Liller

Professor Kerr

En 101-1

14-sept-2010

The Importance Of Our Thumbs

      Thumbs are extremely important when it comes to the life we live and the technological advances we have made as humans. Without good opposable thumbs we would not be able to live what we call a normal life. Our thumbs have some different traits from the rest of our fingers which gives us the ability to pick up and grab objects, which in time we can make tools and advance by doing this. We were not the first with thumbs because all kinds of different primates have and had thumbs but it has evolved over time to what we have and would call a habile hand and a opposable thumb. Without this evolution we would certainly not be where we are today!

      First, what exactly is a thumb and what makes it different from the rest of our fingers? The thumb is the first digit of the hand when a person is standing in the medical anatomical position (which is when the palm is stretched forward). The thumb is the lateral most digit. Our thumb has the following in common with the rest of our fingers. They have a skeleton of phalanges joined together by hinge, like joints, that provide flexion toward the palm of the hand. Also all the fingers have a back surface which features hair and a nail and a hairless palm of the hand side with finger print ridges instead. This is what makes the thumb different; it is opposable to the other four fingers. It only has two phalanges rather than three and it is attached to such a mobile metacarpus, which produces most of the opposability. (Ankel-Simons, Friderun )This is why we are able to pick up and grab objects, which is crucial to our life and existence today. Without thumbs we would not be able to write, cook, play instruments or even make tools to make instruments in the first place.

       We were not the first with thumbs but we have the most advanced and habile hand and thumb and the good knowledge to use it. Phylogenetic studies suggest that the primitive autonomization of the first carpometacarpal joint (CMC) occurred in dinosaurs approximately 365 million years ago. A real differentiation appeared perhaps 70 million years ago in early primates, while the shape of the human thumb CMC finally appears about five million years ago. The result of this evolution is a human CMC joint positioned at 80° of pronation, 40° of abduction, and 50° of flexion in relation to an axis passing through the second and third CMC. ( Young, Richard W. January 2003. )The thumbs we have today came from a long line of evolution. Opposable thumbs are shared by many primates including most simians and some prosimians. This gave them the ability to grip, climb trees, gather and pick fruit which was essential to their living. Some primates with opposable thumbs are pandas, gorillas, koala bears, leisure apes, chimpanzees, and cebids. Opossums’ have opposable thumbs on their feet and raccoons have thumbs but they are not opposable. (Suzanne Kemmer ) Through evolution and changes, we eventually got the habile hands and thumbs that we have today.

     So now that we know the difference between are thumbs and rest of are fingers, and that we were not the first being or mammal to develop thumbs, we just need to know how exactly important they are, and would we be where we are today without them. The opposable thumb has helped the human species develop more accurate fine motor skills. It has also been suggested to have directly led to the development of tools, not just in humans or their evolutionary ancestors, but other primates as well. (G. Stolyarov II) The thumb, in conjunction with the other fingers make humans and other species with similar hands some of the most dexterous in the world.

As for an example look at the Chimpanzees they are extremely smart animals. They also have opposable thumbs as mentioned earlier. They are native to central Africa in the forest. Their opposable thumbs allows them to climb trees which is helpful when hiding from predators and when gathering food like bananas. They also would not be able to peel the banana without the thumb. They get around faster by swinging from limb to limb in the tress which would not be possible either. The most fascinating thing is the use of tools. Chimps use and prepare sticks to fish for termites by poking them into their mounds and waiting for them to grab on. They also use rocks and a log which would be similar to a hammer and anvil to crack open nuts to get their food. (Project Primate, Inc) Chimps are extremely smart but even with knowledge none of this would be possible without their opposable thumbs. Humans can be compared to this, without our thumbs we would not be able to live the life we live today. We would not be able to pick up objects, make tools, grab, climb, or anything like that. So it is certain that our overlooked thumbs helped to spark and innovate new technology that we use today and none of this would be possible without them.
       The thumbs we have today are extremely important to our existence and life style today. Without our human hands basically everything we do today would not be possible. We would not be highly civilized like we are today. We would not be able to make or grip tools to evolve and become more efficient and smarter as we are today. So whether it was evolution, adaptation or just our luck of being born with our habile hands and thumbs. We are extremely lucky because we may not of even still exist without them because of how essential they are to our living.