Free «The Beginnings of Humankind» Essay

Apes and human beings are two different creatures which form a part of the ecosystem. Apes are the primates that belong to the family pongidae and they are characterized by long arms, broad chest and an absence of the tail. They include the chimpanzee, gorilla, gibbon and orangutan. While human being is a man of the species of Homo sapiens, it is distinguished from other animals by its large brain capacity, intelligence and the power to articulate speech. Even though these two creatures are genetically different, they have the common features that can be compared; the dentition, jaws, skull and so on as observed by Johanson and Edey in their book; Lucy: the beginnings of human kind.

In terms of their dentition, the scholars noted that apes have larger developed jaws with the lower jaw being fairly deep and the two halves fused together in the front. Their dental formula resembles that of the old world monkeys; I2/2; C1/1; P2/2; M3/3 = 32. Their teeth is composed of the shovel shaped incisors and the prominent canines; with the rear edge of the upper canines honing against the edge of the first lower premolars. The molars are composed of 5 cusps with a complex arrangement of ridges on the grinding surfaces. On the other hand, human beings’ teeth are arranged in upper arch (maxillary) and lower arch (mandible); forming a shape which is known as the Centenary Arch. Maxilla is firmly attached to the skull while mandible just forms a joint with the skull.

The dentition of a human being is also composed of the primary and permanent teeth. However, the primary teeth are replaced by all permanent teeth at the age of 12-13, whereby the permanent dentition is composed of thirty two teeth. These teeth are also classified as incisors, canines, premolars and molars; each with its specific adaptation for a specified function. They also have a special consistent arrangement that distinguishes them to the apes. The human beings’ teeth are arranged in a manner in which each category lies directly opposite to the ones in the other jaw. For instance, the canines of the upper jaw rest on the ones of the lower jaws and so on, when the mouth is shut.

Concerning the skull, the ones for the apes have flattened faces with complete and forward pointing eye sockets which are very bony and with a plate of bone separating the orbit from the jaw muscle. Their skull also has no chin and the nose bone is flat, while the foramen magnum has crests and is ventrally placed to underneath the skull. On the other hand, the human skull is very different in that it has a smooth-domed shape and is without many crests, as is the case with the apes. The skull is also wider at the top and narrower at the base with a larger brain cavity than that of the apes. It is also made up of two pairs of bones; the cranium and facial bones. Finally, it is noted that the human cerebrospinal system is highly developed for manifestation of self-conscious intelligence.

Hadar and Laetoli are one of the best known archeological sites where a lot of fossils claimed to be for the ancestors of man have been discovered over the years. Hadar is located in 300 kilometers north east of Addis Ababa, Ethiopia and it derived its name from the Kada Hadar tributary; which is a tributary to river Awash. Here, many discoveries about the Australopithecus have been made, including that of the crude stone tools which suggest that the hominid might have lived during the Stone Age. On the other hand, Laetoli is located in Tanzania, about 50 kilometers south of Olduvai Gorge.

According to the analysis carried out by Donald Johanson, Tim White and their colleagues on the hominids’ fossils found in Hadar and Laetoli, these fossils resemble more human beings than the apes. For instance, the fossils found in Hadar by Donald Johanson which were that of the Australopithecus Afarensis (Lucky), had many similarities to the human being anatomy. These fossils were discovered in 1974 and are claimed to have existed between 3.9 and 3 million years ago. The dentition of Australopithecus is said to be more manlike than apelike. It had got large teeth with the back ones being larger than the front ones; just like in case of human beings. Its canines were also larger and pointed just like that of the humans. This is said to have been an adaptation to tearing and eating of flesh. Its molars were also in an ascending size and with serrated roots, just like that of human beings’. Therefore, the shape and arrangement of the entire teeth were closely in resemblance to that of human beings than the apes.

When it comes to the jaws, this analysis indicated that this hominid had slightly protruding jaws which almost resembled the ones for the human beings. While the apes had very larger and much protruded jaws; which were also stronger as compared to that of the modern man and Australopithecus. The jaws were also shaped in a way that they were in between the rectangular shape of the apes and the parabolic shape of the modern man’s; parallel post canine tooth rows. The analysis of the skull of this hominid by the team also revealed a closer resemblance to human beings than the apes. It is said to have been big with a higher capacity (375 to 550 cc.) to that of apes. The skull was also big, but with a round shape, just like that of the human being. Finally, the attachment of the skull to the jaws is almost similar to that of man than to the apes.

Having done this analysis, a conclusion was made that the Laetoli hominid was also an ancestor to the modern man. That is because this hominid resembles the Australopithecus. The Laetoli fossils included the canine tooth, which was found in by Louis Leakey in 1935 and the upper jaw borne with a couple of premolars in it by Kohl-Larsen in 1938/39. They also include the lately discovered artifacts, such as the forty two teeth with slight attachment to jaw bones and the mandible with nine teeth in 1974 by Mary Leakey and a Kenyan, Karnoya Kimeu. However, the most unique discovery in Laetoli was that of hominid footprints, which were discovered by Mary Leakey and her colleagues.

The team claimed that these footprints had been formed and preserved under a combination of events; volcanic eruption, rainstorm and another ash fall. All these artifacts are claimed to have existed between 3.76-3.56 million years ago. Even though there were so many footprints which could be of some other animals, such as the elephants, baboons, and birds; these ones were very unique, as they resembled the man’s feet. These footprints were later studied by Tim White in the same year and his conclusion was that they were that of an erect ape and that they closely resembled the feet of the Lucky, which had been discovered in Hadar by Johanson and his colleges.

Based on the similarities, Johanson and Edey noted that the hominids could be of the same species. This was backed up by the fact that the earlier found fossils also resembled the ones which were discovered in Hadar. They both demonstrated the close resemblance to human beings. For instance, the feet have an arch-bending of the sole of the foot, just like in case of the human beings unlike the apes which did not have it. Its toe was equally not as big as that of the apes, which had a mobile big toe. It also had a lateral transmission of force from the heel then to the base of the lateral metatarsal like the human beings. These Laetoli fossils have also demonstrated resemblance to those from the other Australopithecus artifact sites, such as Turkwel and Maka, which existed 3.4 and 3.5 million years ago respectively.

Having carried out a thorough analysis of the fossils from Hadar and Laetoli, Donald Johanson, Tim White and their colleagues, one compared them to the features of the apes and the human beings. Their interpretation was that Australopithecus is a direct ancestor of man, and that the apes have not any genetically relationship to human beings. This is because the body features of Australopithecus and that of human beings closely resemble each other. While the body features of the apes neither resemble human beings or this hominid. These facts were very influencing towards their interpretation.

Conclusion

It can, thus, be concluded from the book Lucy: the beginnings of human kind that, Australopithecus afarensis is the direct ancestor to human beings, since it had a closely similar body features to that of human beings. However, the apes, which are normally thought to be the part of the human ancestors, are not. In addition, it is also true that the human ancestors must have lived in Africa and that they were free to walk and change residence. This is because the Australopithecus’ fossils were discovered in different geographical regions within the African continent.