An Inquiry into the Origin of Modern Humans: An Exercise in Self Clarification

Lucy (Australopithecine)

Introduction

In determining when modern humans originated, anthropologists worldwide have discovered what is considered to be some of the oldest known fossils in relation to the question of human origin. This great wealth of information to the inquiry of this topic has been discovered within the many unspoiled plains of Africa. Known as ‘The African Exodus,’ it is here that many anthropologists believe our primary ancestors originated from around 10,000 years ago. If this is accurately accountable, then the issues of culture and race pose new meanings among many of the sociological structures within our many present societies.


The Blood Split

The most important issue at the moment for anthropologists is to the origins of people like us, otherwise known as Homo Sapiens. It was in the early 1960’s with the introduction of molecular evidence, that anthropologists discovered a close genetic link between human beings and African apes. This discovery led them to believe that a genetic split between the two occurred as far back as 15 million, and possibly 30 million years ago. But in 1967, Berkeley biochemists Allan Wilson and Vincent Sarich discovered that by comparing human and chimpanzee blood, human blood was seen to have contained protein structures dating 5 million years old. With this discovery, the anatomical blood split was narrowed down to 5 million years. Thus, it was through this genetic study that an important link was established in the emergence of modern humans.


The Anatomical Discovery

With his discovery of Lucy in 1973, Dr. Donald Johanson made a further break through in the ancestral link between humans and apes. His unique discovery showed one anatomical feature that differed from all of her other predecessors: the ability to walk up right. Lucy, an australopithecine of approximately 3.5 feet tall, possessed a locking knee joint similar to our own. This unique feature enabled her to stand in the up-right position and attain bi-pedal motion. In contrast to this feature, the ape knee joint does not lock, and as a result mobility is only made possible with the use of all four limbs. This new discovery established that around 3.2 million years ago, our predecessors had the ability to walk in the up-right mode. Twenty years later, a skull, similar to that of Lucy’s, was found. Due to the fact of the brain size being only one-third the size of a human brain, it was quite clear that this ancestor was not human but more so, that of an up-right walking ape. This discovery narrowed the date previously estimated by Wilson and Sarich by approximately 2 million years.


In the development of speech anatomy, the British anthropologist Kenneth Oakely, in 1951, suggested that as far back as 35,000 years ago, the first appearance of a modern language could be related with the sudden appearance of art and technology. This was a clear signal to the emergence of humanity, as we know it today. Further developments show that early hominids could not speak due to having a smaller sized brain. In his recent studies, Philip Lieberman of Brown University believes that in contrast to the modern larynx position of the chimpanzee, which is situated high in the throat, that at some point in human evolution the larynx (in a similar position) gradually began to descend from its previous heights to a lower position in the throat. This in return permitted Homo Genus to achieve a more complex variety of sounds. He also concludes that a more modern throat didn’t evolve until around 500,000 years ago.[1]


The Evolution of ‘Homo

With a brain size two-thirds the size of a modern humans, Homo Habilis would not have sustained itself on a purely vegetarian diet. Due to the increase of brain size, the need for greater calorie consumption led these ancestors to scavenge for food.[2] Living of the bone marrow of dead animals, Homo Habilis gradually developed the need for the use of the necessary tools in order to survive and improve the quality of life. Having gradually developed an ability to express itself through means of art (cave paintings) and cultural improvements (tool making, hunting etc), Homo Habilis represents the first ancestor to achieve an improved standard of life through the gradual awareness of its progressing state of intelligence (increase of brain size).


In Kenya in 1984, the skeleton of a young boy was discovered by Richard Leakey dating 1.6 million years old. Otherwise known as the Turkana boy, this skeleton posed similar features to that of modern humans. With a slightly thicker skull, protruding jaws and prominent eye ridges, the most important discovery however came from the size of his pelvis bone. Similar to that of humans, this discovery shows that Homo Erectus babies would have been born without a fully developed brain. Although with a brain size larger than that of australopithecines, Homo Erectus’ brain size still remained smaller than that of modern humans-some 900 cubic centimetres compared with the average 1350 cubic centimetres of Homo today. This would also infer that the modern day standard for the care of newly born babies began with Homo Erectus.


Having inhabited the earth up to 500,000 years ago, the basic anatomical features of Homo Erectus continued up until then. With the brain size gradually increasing to within 250 cubic centimetres to that of a human brain, Homo Erectus populations began to spread out of Africa, into Asia, and gradually into Europe. However, there is no concrete evidence that links Homo Erectus with the first full human remains found, dating back only 34,000 years. There is a more popular theory, which suggests that Homo Erectus populations in Africa, Asia and Europe were replaced by Homo Sapiens who evolved in Africa.This theory is also supported by anthropologist Chris Stringer who also suggests that Neanderthalis may have lived with Homo Sapiens within the many regions of Europe for about 60,000 years until the Neanderthal period gradually ended some 35,000 years ago.


The Multi-regional Hypothesis

This first theory was raised by the anthropologist, Milford Wolpoff, who believed that the origin of modern humans began with Homo sapiens emerging wherever populations of Homo Erectus had previously been established.[3] According to this theory, Neanderthals are the crucial link between Homo Erectus and Homo Sapiens. Using the evidence of the Kebarra and Qafzeh caves in Israel, Wolpoff concludes that Neanderthals and Homo Sapiens at one time lived there. Neanderthals until 60,000 years ago and Homo Sapiens until 40-50,000 years ago. This evidence seems to support the premise that modern humans evolved from the Neanderthals. However, during the late 1980’s, a new form of fossil-dating known as electron spin resonance and thermoluminesence, showed that the modern human skulls from Skhuland Qafzeh actually pre-dated the extinction of the Neanderthals by 40,000 years and thus could not have possibly been their successors.[4] With this weakness emerging in the multi-regional theory, the ‘Out of Africa’ theory seemed to confidently stand its ground among the many surrounding theories on the origin of modern humans.


The Out of Africa Hypothesis

This theory was proposed by anthropologist, Chris Stringer of the Natural History Museum of London and suggests that modern humans originated out of Africa and gradually dispersed out into the whole world (about 100,000 years ago) replacing existing populations of Homo Erectus and archaic Homo Sapiens.[5] Evidence insupport of this theory was found in the sub-Saharan region of Africa; the Klasies river mouth, and in Israel; the Skhul and Qafzeh caves. Here in these areas the oldest fossil remains of modern Homo Sapiens were found,dating back 100,000 years. This theory is sufficiently supported by the above fossil evidence, which in return provides sufficient genetic material for Molecular Genetic testing.


Mitochondrial DNA

Having previously discovered the anatomical blood split in 1967, the Berkeley biochemist Allan Wilson carried out a series of studies in 1987 on mitochrondial DNA.[6] He concluded that our direct human ancestors originated some 150,000 years ago,from a single African female, otherwise known as ‘Mitochondrial Eve.’ This evidence also revealed that there couldn’t have been any interbreeding with premodern populations. Apart from upholding the ‘Out of Africa’ theory and further contradicting the ‘Multi-regional’ theory, this evidence suggests that Homo Sapiens completely replaced ancient populations such as the Neanderthals.


Conclusion

Having covered the many aspects to the inquiry of when modern humans originated, a gap of some 450,000 years still remain unfolded within the parameters of anthropology. As the genetic investigation began to unfold with Sarich and Wilson with an estimation of 5 million years gradually being narrowed down by more recent genetic developments showing stronger emphasis on the origin of modern humans dating from around 200,000 years. However, the most important feature in the development of modern humans is the use of language. With the development of language, due to the increase of brain size and the gradual repositioning of the larynx, we see that modern humans gradually began to project certain forms of expression from within themselves in the areas of personal awareness and feelings. With this new ability, speech, art and culture became the forefront of expression towards the maintaining of one’s life in relation to how one should live for the good of one’s own environment and culture. It was only through the ability to understand the environment in which they lived that modern humans gained the ability to grasp and achieve control of it. This in return led them to an eventual understanding of the world in which they lived in. Evidence of this is clearly seen in the many aspects of the cave murals painted by our modern ancestors, which in turn enlighten us by clarifying one of the many aspects of human expression. It is only through our own presentability to communicate, using the various gifts that we inherited from our ancestors, that we gradually come to know and partially understand our own ancestral journey, which in return helps us to clarify the misleading concepts that divide the whole human race.


If the ‘Out of Africa’ theory is true then the only thing that distinguishes all humans is that of cultural differences, and not racial ones. It is only when we openly dwell into our past and try to discover the ‘when and where’ of our ancestral background that one gradually sees the fundamental issues that draws and poses newer meanings to the personal clarification of each individual human being. Personally, I believe that a deeper clarification in relation to this issue can only be attained within the philosophical parameters in relation to the ascent of the modern human.


[1] Matt Cartmill, The Gift of the Gab: Discovery, November 1998, p.58.

[2] Previous ancestors to Homo Habilis lived on a vegetarian diet.

[3] Richard Leakey, The Origin of Humankind. (London: Wiedenfeld & Nicholson, 1994) p. 82.

[4] Ibid. p. 86.

[5] Chris Stringer, African Exodus,The Origins of Modern Humanity. (London: Jonathan & Cape 1996) p. 14.

[6] When an egg from a female and the sperm of a male fuse, the only mitochondria that become part of the cells of the newly formed embryo are from the egg. Mitochondrial DNA is inherited solely through the maternal line.


© Niall Markey 2010

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Comments 4 comments

Randy Godwin profile image

Randy Godwin 6 years ago from Southern Georgia

Very concise article! Well written also. May I suggest you make your paragraphs smaller with more white space to give the eyes a break. Enjoyed the read!


niallmarkey profile image

niallmarkey 6 years ago from New York Author

Hi Randy. Many thanks for reading the article. Your input was also very helpful.


LeonJane profile image

LeonJane 6 years ago from Australia

Very well researched and you also have a bibliography, which is probably the first one I have seen here on HubPages.

I agree that scientific/archeological evidence leads us to conclude that humans evolved from Africa. It is also interesting that some variants of our ancestors have been discovered recently, like Homo floresiensis in Borneo.

Great work on a subject that I enjoy reading about!


Crazdwriter 6 years ago

Wow this is a great read. You have provided a lot of great information. I remember when we first heard about Lucy as well. But not so much the other information you provided so thank you. You did a great job!

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