Kenya lies in a strategic place in Africa. Its capital city is Nairobi with a current total population of 39. 11 million it has an area of 224,960 square miles. Two main discoveries in Kenya have made a great contribution to the evolution tree.
These discoveries were made in the year 2000 by an association of international scientists, most of who were from France in collaboration with scientists associated with the National Museums of Kenya (NMK), working under an umbrella project known as the Koobi Fora Research Project lead by Louse Leakey who was at the time of the discoveries affiliated to the National Museums of Kenya and their findings were published in the science journal Nature. These studies preceded the earlier controversial findings by Kenyan researcher Richard Leakey on the exact age hominids found on Koobi Fora Area that lies east of Lake Turkana.
The first specimen to be found was unearthed from the grounds of Kapsomon in Tugen hills that are found in the Kenyan district of Baringo in October 25, 2000. The main parts of the human that were excavated included jaws that contained teeth, upper and lower teeth that were also isolated from each other, and both the arm and finger bones. Initial studies on the finger bones seemed to lead to the suggestion that the hominid discovered were trees climbers while similar studies on the leg bones established them to be two legged creatures that walked on the ground.
Similar initial studies on teeth showed that the canines were shorter than the apes however; they were longer if compared to the current human canine. This probably indicated that they lived on wild fruits particularly hard-skinned fruits. The leg bones on initial observation seemed to have chewed probably by a large carnivore that used to feed on the individuals who existed then. The researchers thought the carnivore might have been a cat for the simple reasoning that the cat feeds on its catch while on a tree and it’s during this process that the remains fell on the water below.
Their research findings were published in 9th august 2007. The studies were done on samples that were found in Turkana which is in the Northern dry Kenya. Scientists who were studying the evolution history in Kenya reported on their findings disputing on early findings that Homo habilis and Homo erectus evolved one after the other being in a straight line to Homo sapiens. In stead their analysis based on two specimens, one being a Homo habilis dated 1. 44 million years, this being the youngest species ever found by scientists who were studying the evolution of human, and a homo erectus dated 1.
55 million years ago, lived concurrently alongside each other for an estimated period of five hundred thousand years. This disqualifies the thought that Homo habilis evolved from home erectus consequently rearranging the initial straight line to Homo sapiens. This indicated that there was an overlap between the Homo habilis and Homo erectus ages and further, it indicated that the fact they the two species managed to live concurrently on the same lake basin then it is right to suggest that they probably had different ecological niches as a result avoiding direct competition that would have led to elimination of one of the species.
Stringer Chris one of the scientists involved in the study, who was then studying at the Natural History Museum in London in the field of human origins suggest the possible life styles. In his view the larger and more mobile erectus was possibly a more active hunter while the less active and smaller Homo habilis was a scavenger. This study took several years to prepare the specimen so as to be exactly sure of the identification of the specimen. It took around seven years for the group of scientists lead by Leakey to analyze and announce the results.
This interpreted to the view that almost two to three million years ago both Homo habilis and Homo erectus must have originated from a common ancestor. This common ancestor is thought to have lived the age dating almost two to three million years ago, a time that there is no much fossil information. This discovery further indicates that the early general understanding that man evolved from a more ape like being to a more human like being is still poorly researched. However, the discovery does not contrast much from the early thought that homo habilis is the direct ancestor of Homo sapiens.
The Homo erectus fossil discovered at Lake Turkana, dated 1. 55 million years ago, was a surprise discovery, according to Dr. Spoor a professor of professor at the University College London concerned with evolutionary anatomy; the skull had a striking feature as compared to early discoveries: it was the smallest. This small size was relatively close in size to Homo habilis than the previously discovered Homo erectus species. This new finding made scientists to consider re-examining early skulls they had already collected from various parts and dozes of partial fossils which together totaled to thirty in number.
However, its neck, jaw and teeth and the cranium with a distinctive feature had the characteristics that indicated it was a Homo erectus. In addition, the skull of the individual that was found in Kenya was probably an adult in its young ages or a “sub-adult” in its late ages the scientists estimated the age to be between 18 and 19. The early discoveries had indicated that the large skull of the Homo erectus was a clear indication that home erectus was the most recent in the ancestry of the human being the only difference being that human beings had a larger brain that the former ancestor: Homo erectus.
However, the small skull changed this view suggesting that Homo erectus was less human like than earlier assumed. However, different reporters on the Lake Turkana tend to give different opinions on the small size of the skull of Homo habilis that was found. One such reporter is Susan Anton an anthropologist at the University of New York. In her report she postulates that the small skull is an indication of the varying in skull sizes of erectus specimen with more emphasis on the differences between the male and the female of the erectus species.
This difference in the two is what she called sexual dimorphism. She further writes to illustrate that on average the human males are in general almost 15% larger than their female counterparts. This same characteristic applies to chimpanzees and gorillas as well. The theory of sexual dimorphism, lead to other anthropologists to come up with other views for example; Dr. Lieberman of the Harvard university suggested that the initial discoveries of homo erectus must have been male since they were large in size while the specimen that were found at Lake Turkana are likely to be females due to small size.
Susan Anton attributes sexual dimorphism to either reproductive strategy or sexual selection. In an example in support of this view she documents that in the silverback the male are far much large than females and one male usually has several females. In contrast in male gibbons are almost similar in size to their female counterparts consequently they mate in pairs. In other words in the a primate family where the male and the female have the same size skull the male tends to be monogamous whereas a family that has different sizes the male tends to be polygamous.
Conclusion The discovery of fossils in Kenya and the rest of Africa especially Ethiopia and the subsequent dating procedures have provided a wide array of time frame work which has given a new dimension in answering questions of the origin and evolution of hominids. With improvement in dating techniques it is now easier to estimate, without a lot of doubts, the ages of a given carbon containing specimen as compared to earlier estimates that were in most cases were debated hotly before a consensus would be agreed upon.
The improvement in dating techniques can be attributed to the incorporation of 40Ar-39Ar dating technique. With the new discoveries the evolutionary tree seems to scientists to be chaotic rather than being heroic. This is because the old evolution theory where it was thought that origin of man started from homo habilis to home erectus and finally to modern man or homo sapiens seems to be proven wrong and in a more simple manner. The new discoveries have further brushed off the idea that human beings evolved from Neanderthals.
It is important to note that as new discoveries are made the evolutionary tree will keep on changing. However, according to Kimbel this should be considered as a basis for getting more convincing evidence, getting questions answered more clearly and formulating more clearer theories.
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