The Origin of Mankind – Genetics

Africa is widely recognised as being the Cradle of Humankind, the origin of all human life as we know it today. This theory is largely supported by archaeological findings, including the fossilised remains of our earliest ancestors’ bodies and the tools and implements they used in prehistoric Africa.

However, there are other ways of confirming this continent as being the Cradle of Humankind, and one of these is through the genetic history of the African ancestors. There are two parts of the genetic code of mankind that have not been altered by the widely accepted theory of evolutionary development. These are the MITOCHONDRIAL DNA and the Y CHROMOSOME of any human being.

Molécula de ADN 3D (Ádico DesoxirriboNucleico)
Image of Molécula de ADN 3D (Ádico DesoxirriboNucleico)

The evolutionary development of humans, by definition, defines each generation, making each one a little more advanced than the last. These two parts of the genes are those that stay constant, regardless of how the rest of the genetic code modifies itself to meet with environmental and social changes. So, this theory asserts that all humans have received their Mitochondrial DNA from one common woman and that all men have received their Y chromosome from a common man. These two ancestors are nicknamed Mitochondrial Eve and Y-chromosomal Adam by scientists in favour of this theory. She is believed to have roamed the earth 160 000 years ago while he followed about 100 000 years later.

The San people that once occupied and traversed much of Southern Africa are, as a society, those who display the qualities of being of the same Mitochondrial DNA haplogroup. Likewise, the Eastern African peoples, called the Sandawe, and the Mbuti people display the same genetic code. This haplogroup is known as L0 to scientists. From this group descended the haplogroups L1, L2 and L3. These groups came from the original Adam and Eve, but branched out to form new human “races”, as we would broadly define them today. These “L” groups are, for the most part, confined to Africa, while the M and N groups, which came from the L3 group, usually refer to the human beings outside of this continent.

All Y haplogroups (except A and B) are referred to as belonging to the macro haplogroup CR. Those adaptations and mutations that characterise this group are believed to have happened before these humans began their exodus from the continent, and their habitation of a wider spread area. The descendents of this group are called the DE macro group. This particular group only exists within the continent of Africa. Of all the haplogroups under the CR group, C displays unique mutations, which differentiates it from the groups D onwards. These unique characteristics are believed to have formed 60 000 years ago, just after the migration out of Africa occurred.

Haplogroup F has some mystery around it, as researchers and anthropologists are not entirely in agreement about whether it originated in North Africa or South Asia. As it is believed to have evolved some 45 000 years ago, its origin has a significant bearing on the migratory patterns in Africa. If it was to have originated in North Africa, this would indicate a second migration out of Africa at that time.

Effects Of Climatic And Environmental Changes On Ancient African Civilisations

Hundreds of thousands of years ago, the entire planet earth looked very different to what modern man experiences today. Continents were not yet divided, and the vegetation and animals were different. Significantly, the climate was also vastly different to what it is today. Climate plays an integral role in determining the plants and animal that live in a certain areas, as well as how habitable a place is for human beings.

In fact, even the theory of the evolution of man was dependent largely on the climatic influences on our ancient ancestors. It is hypothesised that the ancient versions of man were forced to walk upright, lose body hair and develop their coordination for survival in a changing environment. New skills also needed to be learned as farming techniques and living habits had to be adapted.

Ancient Africa experienced major vacillations between mega-droughts and Ice Ages, although these fluctuations occurred over thousands and thousands of years. As humans continued to develop and evolve through these phases, they needed to make major adaptations, not only to their ways of life, but also to their personal body structure. Prior to 135 000 years ago, the whole of Africa was lush and fertile, with a tropical climate. Then, the most intense mega-drought ever to occur hit the continent in the period referred to as the early part of the Late Pleistocene epoch. This is believed to have led to the migration of most of our human ancestors into other areas that were more habitable and fertile. Lake Malawi has been used by scientists as a rain gauge to ascertain water levels in ancient times. Research has shown that, during this mega-drought, the lake’s level dropped at least 1968 feet, or 600 metres! Evolutionists claim that this severe lack of water not only pushed ancient man from the area, it also forced aquatic animals (such as fish) to develop the facilities to be able to survive on dry land, thus evolving into land animals.

As people flocked out of the continent, only a very small proportion of this specific generation remained. Humankind as we know it is widely believed to have come from these few remaining on the continent, who evolved significantly and in response to the climatic changes.

These conditions continued until about 70 000 years ago, when the climate was again characterised by wetter conditions. These led to the growth and renewal of fresh vegetation, as well as an increased water supply to the region. More people were in the area during this time of abundance, and the population grew. This increase in numbers eventually led to migrations due to space limitations and the ownership of land.

Then, about 20 000 years ago, an Ice Age overcame the entire earth. This meant that the planet underwent a long-term period of cold temperatures over most of its surface. In places like North America and Eurasia, giant ice sheets covered enormous proportions of the land, making it impossible to farm and, sometimes, even live in these areas. This final Ice Age lasted for about 9 500 years. It forced most of the populations to migrate to the highlands, where they would be relatively protected from the ice sheets. Again, these civilisations had to adapt their farming methods, and change their diet, social habits, clothing and migratory patterns. This forced an evolution to a certain extent. Body hair was necessary to keep people warm, their skin lightened due to a lack of the harsh rays of the sun that they experienced during the mega-droughts, etc…

When this Ice Age came to an end 10 500 years ago, areas like the Sahara were left fertile and healthy. This made it and the other areas like it the ideal spots in which to settle as ancient man began to descend from the highlands. Animals and plants thrived in this environment, which made it very desirable in the eyes of mankind. The abundance of food, water and sunshine again changed the habits and physical structures of our earliest forefathers.

These conditions lasted for some time, but the Sahara in particular continued to experience fluctuations between humid and dry conditions. These eventually left the entire area unable to yield crops or sustain life for any extended period of time. Today, it remains a large stretch of desert. Then, approximately 2500 years ago, the group of people who had made their home in the Sahara began to follow the direction of the Nile River, which held promise of a rich water supply. The arid conditions of the Sahara and its surrounds continue to the present day.

Africa has, since prehistoric times, proven to be a place of fascination, life and evolution. Changes in the climate were often dramatic, and these were, to a great extent, responsible for determining the ancient civilisations that inhabited this vast continent. It is no wonder that many researchers and scientists maintain that Africa is the Cradle of Mankind, and research continues to yield fascinating evidence of this theory.