Professor Susan Hodgins
Composition I 1052
16 September 2014
Africa, the cradle of life.
For the past two centuries, scientists have tried to investigate the human family history, digging in the past as Archaeologists did and still do. Archaeology was the first scientific method to be used as tool for this research. In the last fifteen years though, a huge progress has been made and great discoveries have changed our personal thinking.
Genetics, the study of genes, allowed scientists to gather more information and almost fully understand the history of our species.
This "new" science studies the human blood and more specifically human genes, molecular units of DNA grouped in chromosomes located in every cell's nucleus of our body. The human DNA contains all the instructions necessary for the organism to work, it's the blueprint for all inherited human characteristics.
The documentary "Journey of Men" (2003) traces the earliest human migration on this planet, as shown by our genetic roots. This informative film, full of surprising news, is based on the work of Spencer Wells, who is both an innovative geneticist and an enthusiastic host.
In his career he works with Luca Cavalli Sforza, who gathered up blood samples from many populations around the globe to learn about our ancestors and his results led to a revolutionary discovery, humans are all related to one common progenitor.
In the past, this was not a fully accepted theory but today most of scientists agree with it, making the biological human evolution a today's revelation.
According to Sforza and many other geneticists, the human evolution began in Africa ( precisely in the Great Rift Valley area ). His studies reveal that African tribes' blood samples could give a clearer picture about our distant family.
It is believed that at some point in the past, catastrophic events occurred, such as ice ages, one more devastating than the others and the climate changed all over the world, becoming an hostile environment so that those first men were forced to leave their homeland migrating outside the African continent with the hope to survive.
Spencer Wells questions himself about this amazing and hard journey, whose men populated the entire world, he wonders how they were able to survive and become the most successful species on the planet.
He then decides to retrace the steps of our ancestors, travelling to Africa, where all began. Once there, Spencer met those who are believed to be the direct descendants of our African progenitors, a small tribe living in Namibia, the "Sun Bushmen".
He explains, through genetics and anthropology, how this tribe could represent exactly our ancestor's abilities to survive over other groups of primitive humans. What Spencer finds there, it's a small group of people with their own unique and ancient language; without any modern technology they survive hunting and gathering food, living away from any society that could influence them. The time stopped for them and this allows us to studying these people and understand better what were the chances for our ancestors to leave Africa and survive at the ice ages. During this period, the sea level dropped so that more land emerged and the African ancestors were able to pass through Middle East, arriving in India and eventually also in Australia.
Spencer then heads to India to find the missing genetic link between Africans and Aborigines from Australia. Following the male lineage of an Indian village, he finds the genetic marker that finally proves the early African coastal migration, passing through Australia as well.
More studies were conducted on blood samples from all over the planet and scientists discovered that the African group split up, 10% of them reached Australia but the rest 90% gave birth to the descendants of European, Asian and North American populations.
The African progenitors took the Middle East's route, a bridge that led them to the conquest of