|
HOW TOOLS TRANSFORMED PROTO-HUMANS
INTO MODERN HUMANS
According to archeological and physical record, tool use has had an enormous effect in the transformation of proto humans into modern humans. What stimulated tool use was the proto humans intrest in new and easier ways to do things. With the introduction of tools, body morphology changed and reproductive fitness increased. Evolution did not happened over night. It took 4.5 million years for humans to get where they are today.
Scientists have concluded that about 3.5 million years ago, there was the first proto human. A proto human resembles extinct hominid populations that had some but not all the features of a modern homo sapien. Such features were prolonged moments of bipedality, change in the pelvis and the reduction of the sagittal crest. (Diamond 1992 pg 34) In order for this proto human to evolve into a human, it needed tools. Some of the tools might have been discovered by accident or by early creative geniuses? The way they discovered the tools is unknown, but the changes the tools made were to the physical morphology and the body behavior. They began to walk upright, gathered supplies, cut food, and used weapons.(Diamond 1992 pg. 40)
About 3 million years ago, after generations of learning how to use these tools, the hominid came out of the trees, and stayed mostly on the ground. The animal had an
abundance of food and water and lived in a population of; on the ground proto-human animals. Some adapted to ground life and started to become bipedal, but more than half of them stayed on all fours. The bipedal hominids vision increased, making it able to see and do more. It obtained the ability to use weapons more effectively and efficiently because it had arms with agility. It found all the good meat and valued resources then eventually took over the whole community. Soon after the bipedal creatures gained control the hominids on four legs die off, precisely because they could not evolve quickly enough and produce healthy, if any, offspring. The bipedal community grew into the hundreds and thousands. Tough, healthy, and agile hominids, the strong survived and the females produced healthy offspring which is called reproductive fitness. The mouth became smaller and the brain increased in size. More brains equaled better tools, which lead to a faster, more efficient evolution.(Diamond 1992 pg 12)
According to the bone and fossil evidence that I have learned, this is my interpretation how evolution might have happened. When a species develops tools, many things can a will change. The definition of a tool is, performing or facilitating mechanical operations.(Websters Ninth New Dictionary) Take for instance a hominid that walks on all four limbs. How easy would it be for a hominid, without agile arms, to mechanically operate a tool? It would be very difficult. This type of arboreal hominid, probably lives in a tree, swings from the branches, vision is not great, and is mostly a vegetarian. After the proto human began to walk on two feet there hands became free and moveable. Now give this hominid a sharp stick or a blunt object, practice as how to properly use it, and
pg 3
maybe arm agility. Then over time (about 3 to 2.5 mya) the animal becomes a hunter, being able to strike a predator, protect, and gain control over resources.
In the movie 2001 Space Odyssey,(Anthropology 100 9/5/97) Stanley Kubrick gives his interpretation on how we evolve. The movie shows groups of stem-primate type creatures who represent early proto-human communities. The creatures begin to explore their environment finding resources and developing new ways to do things. The communities battled other primate communities for the natural resources in their environment. One of the primates begins to break some objects with a bone it picked up. The primate then realizes that this bone can do major damage. When one community learns to use bones as weapons, then that group can take over the resources in a certain area and be selected for, which increases reproductive fitness. This scenario could have happened but the truth is nobody knows exactly how and why things turned out the way they did.
Not just hominids use tools. Wood-peckers, vultures and sea otters are among the other animal species that evolved by using tools to capture food, but these creatures are not as heavily dependant as we are.(Diamond 1992 pg 36) Without tools evolution might have taken much longer. Tools had a major affect on teeth, hair, behavior, and even language.(Diamond 1992 pg 12) When developing and using tools, the species takes control over the environment and makes it work for them.
One major change in the physical aspect of evolution is the morphology of the body. Proof of this came from the discovery of Lucy, the 2.5 million year old homo-
pg 4
erectus, half monkey half human.(Haviland Eighth Edition pg 140-141) The head grew so the brain could expand, allowing hominids to think and create new tools. The mouth became smaller and teeth turned into herbivore teeth, enabling speech to develop. The widening of the pelvis was a major and critical change, it allowed the animal to walk on two feet. This change in the pelvis allowed all proto-humans to stand at long periods of time, making it more free and taller which increased vision. Having the features of better vision and maneuverability made it easier for the hominids to control the environment instead of letting the environment control them. Being able to control the environment leads to better food, healthier bodies, better reproductive fitness and increases the quality of life.
If you think about how primitive early hominids were and you look at modern day humans. How could a bone or stick make so much of a change in our bodies? The whole process is amazing and until science gets the whole story, we may never know the whole truth about how tools shaped our lives today. Who would have thought that a 0.1 percent difference in DNA could have made such a change? (Diamond 1992 pg 54) One thing is for sure, without tools evolution would have taken much longer.
pg 5
Bibliography
BIBLIOGRAPHY
1. Haviland, Anthropology Eight Edition. Harcourt Brace, 1997
2.Diamond, Jared The Third Chimpanzee. HarperPerennial. 1992
3. Various Internet sites
Word Count: 1031
|
|
