The evolution of man and human race

The Evolution of Man

The human race has evolved dramatically over the last few centuries, from an apelike being to the modern man. Paleoanthropologists, or scientists who research the evolution of man, have discovered that such traits have been shared by different 'human beings' at various periods of evolution. Paleoanthropologists believe that humans are pirates, which supports the idea that there are hereditary and physical traits that are shared by personalities at different periods of human evolution. One of the major elements that can be used to analyze the characteristics of man along the evolution process is the skull size and the brain size. In this paper, the skull size, as well as the brain size of the Australopithecus, the Homo habilis, and the Homo sapiens, will be analyzed and after that, a comparison of the same will follow.

The Australopithecus

The Australopithecus are considered as the oldest human ancestors that lived approximately seven million years ago. The human beings then resembled apes, hence, the reason behind the term ‘pithecus,’ which means ape. The average weight for man then was considered to be fourteen kilograms. The Australopithecus are considered as the oldest human ancestors that lived approximately seven million yams. The Australopithecus skull closely resembled that of the apes. For instance, the skull had a sloppy forehead and brow ridges (above the eyes) that could be easily noticed. The center of the skull was the root of the spinal cord. Their crest was also very small, and it was situated on the back side of the skull. Additionally, the Australopithecus’ jaws were quite narrow and long. The males also had a sagittal crest that was located on the top of the skull, which played a significant role in ensuring that the jaws were firmly attached to the skull (Australian Museum, 2016). The brain size of the Australopithecus was quite small and is approximated to have been 430 cubic centimeters. In addition, it is argued that the Australopithecus’ brain was equivalent to 1.3 percent of their overall body weight.

Figure 1: A Skull of the Australopithecus Afarensis. Image Location https://australianmuseum.net.au/Uploads/Images/9371/DSC_0025_big.jpg

The Homo habilis

The Homo habilis forms the first generation of the modern day man. The term ‘homo’ is used to mean ‘human’ while ‘habilis’ means ‘able.' The paleoanthropologists argue that the Homo habilis existed between two million years ago and 1.5 million years ago. The major characteristic of this human generation is that man had started manufacturing various tools that were carved from stone. The Homo habilis brain capacity is approximated to be 610 cc and represented 1.7% of its overall body weight (Australian Museum, 2016). The skull was more rounded as a result of the increase in the brain capacity, and its face looked quite small. The spinal cord was situated at the epicenter of the skull’s base, which affirms the bipedalism characteristic of the Homo habilis. The jaws were relatively small in comparison to those of the Australopithecus.

Figure 2: A Skull of the Homo Habilis. Image Location https://australianmuseum.net.au/Uploads/Images/10450/_DSC8940_big.jpg

The Homo sapiens

The Homo sapiens are considered as the genealogy of the modern man, whose existence can be traced to approximately to four hundred years ago. The Homo sapiens are accredited for their use of sophisticated tools. The Homo sapiens’ skull is quite distinctive from those of the earlier human species although the shape varies depending on the environment one is adapted in. The brain capacity of the Homo sapiens is estimated to be 1350 cc and is equivalent to 2.2% of the total body weight. However, it is believed that the brain capacity of the earlier Homo sapiens was quite large as it was equivalent to 1500 cc. A Homo sapiens’ skull has a small bottom and very broad at the top. As a result of its (skull) braincase, it is almost impossible to identify the constriction formed by the constriction of the eyes’ sockets. The skull is also more rounded at its back, which signals a decline in the neck muscles. The Homo sapiens’ jaws are quite short which makes its face seem to be vertical.

Figure 3: A Skull of the Homo Sapiens. Image location, https://australianmuseum.net.au/Uploads/Images/9373/DSC_0039_big.jpg

A Comparison of the Skull Size and the Brain Size of the Three Species

An in-depth analysis of the features of the three species reveals that they had the potential to think and make rational choices as evidenced by the presence of the brains. As brought out in the analysis above, it is also evident that the spinal cords’ of the three species emanate from the center of the skull.

One of the differences that is quite evident from the illustrations above is that the size of the skull gets smaller as time progresses. It is evident that the Australopithecus had a big skull while the Homo sapiens (present day man) has a relatively reduced skull. In addition, the brain size (brain capacity) gets bigger as time goes by. The Australopithecus had a brain with 430 cc while the modern day man has a brain capacity of 1500 cc. It is, hence, evident that the Homo sapiens is quite wise and more knowledgeable than the other species. In relation to the jaw structures, the Homo sapiens have very small jaws than the other species – the Australopithecus has the longest jaws.

Conclusion

The evolution of man dates back to approximately seven million years ago. Since then, man has undergone several stages of evolution key among then being the Australopithecus, the Homo habilis, and the Homo sapiens. Though the evolution took place at different times, it is evident that some major characteristics can be noted among all the species. For instance, the species were capable of making rational decisions, which is affirmed by the fact that all species has brains. Nonetheless, key differences can also be noted among the species. Additionally, the spinal cord of the three species is rooted in the center of the skull, which signals the bipedalism characteristic of the human beings. One of the major differences is that the skull size of the various species got smaller and more rounded as evolution took place, which makes the Homo sapiens (the present day man) has the smallest and the most round head. The jaw structures of the three species also changed as time went by. The Australopithecus had long jaws while the Homo sapiens has very small jaws. In addition, the brain size of the various species also kept on increasing as time progressed. As illustrated above, the present day man has the highest brain capacity (with 1500 cc) while the Australopithecus had the smallest brain capacity with 430 cc. As a result of the high brain capacity, the Homo sapiens is also the wisest and the most knowledgeable among the species.

References

Australian Museum. (2016). Australopithecus Afarensis. Australian Museum. Retrieved from https://australianmuseum.net.au/australopithecus-afarensis

Australian Museum. (2016). Homo Habilis. Australian Museum. Retrieved from https://australianmuseum.net.au/homo-habilis

Australian Museum. (2016). Homo Sapiens – Modern Humans. Australian Museum. Retrieved from https://australianmuseum.net.au/homo-sapiens-modern-humans