Eritrea Danakil Depression – origin of Humanity
by Tsega Medin Scientists agree that human evolution is a lengthy process of change by which people originated from apelike ancestors. Scientific evidence shows that the physical and behavioral traits shared by all people originated from apelike ancestors that evolved over a period of approximately six million years.
Humans have evolved over the past 6 million years, and there were important milestones along the way.
For example: (i) early humans began walking upright before they began making tools,
(ii) a rapid increase in brain size occurred before early humans began using symbols to communicate, and
(iii) all of these traits emerged before humans began domesticating plants and animals.
Early humans first migrated out of Africa into Asia probably 2 million years ago. They entered Europe later, between 1.5 million and 1 million years ago. Species of modern humans populated many parts of the world much later. For instance, people first arrived at Australia probably within the past 60,000 years and at the Americas within the past 30,000 years or so. The beginnings of agriculture and the rise of the first civilizations occurred within the past 12,000 years.
Evidence of the origin of humanity beyond 2.0 million years is not yet known outside of Africa. Africa is the only landmass known as the home of our ancestors 2 million years ago. As a result, it is widely accepted as “the cradle of humanity”.
Early human fossils and archeological remains offer the most important clues about our ancient past. These remains include bones, tools and other evidence such as footprints, hearths, or butchery marks on animal bones left by people. Usually, the remains were buried and preserved naturally. They are then found either on the surface (exposed by rain, rivers, and wind erosion) or by digging in the ground. By studying fossilized bones, scientists learn about the physical appearance of earlier humans and how they changed over time. Bone size, shape, and markings left by muscles tell us how our predecessors moved around, held tools, and how the size of their brains changed over a long time. Archeological evidence refers to the things earlier people made and the places where scientists find them. By studying this type of evidence, archeologists can understand how early humans made and used tools and lived in their environments.
In Africa, the majority of the sites that have evidence of the evolution of our species are found alongside the extended African rift valley. A rift valley is a valley that is created by the splitting of the earth’s crust. Two major rift valleys occurred on the land surface, or in the continental crust: the Baikal Rift Valley in Siberia and the African Rift. The East African rift valley is mainly created by the separation of the Nubian plate and the Somalian Plate, which together comprise the African plate of the African continent.
The East African Rift valley developed during the Miocene 22-25 million years ago and stretches thousands of kilometers across Eritrea, Ethiopia, Kenya, Uganda, Rwanda, Burundi, Zambia, Tanzania, Malawi and Mozambique.
As part of the northern most end part of the rift valley, the land of Eritrea, has unparalleled evidences related to the evolution of our ancestors and other mammals. The now inhospitable places of the Danakil depression of Eritrea were home to our ancestors about 1.0 million years ago.
The Eritrean Danakil Depression is part of the Afar Triangle in the Great African Rift valley, which is a geological depression that is caused by the Afar Triple Junction. The area lies near or below sea level for much of its extent with a “v-shaped” depositional view and with apex into the Gulf of Zula and open to the south towards the central Afar region. It occupies a nodal position between the gulf of Zula, Samoti plains, Bada corridor and the Garsat graben.
The Dandiero Basin, which is named after the main river in the area called “Dandiero”, is the biggest and main basin in the area. It drains together with the Maebele stream from the highest mountains near Amba Soira (2988 meters above sea level) and submerged in the sands of the Samoti Plains. It is part of the extensive lowlands of the Afar depression and covers an area of about 100 square kilometers and extended in the North-South direction. It is surrounded by the Danakil Alps to the east, the Eritrean plateau to the west and the Alid volcanic Mountain to the north. The Alid Mountain is an elliptical structure that rises as a single mountain up to 700m above the flat plains of Samoti and it was formed during the late-Pleistocene uplift. Towards the east of the basin, the Samoti plain is seen covering a large fluvio-eolian sand field and alluvial deposits. Towards the south and west of the basin the Neoproterozoic basement rocks appear at large.
The lowlands of the Depression are affected by heat and drought. There is no rain for most of the year, and annual rainfall averages range from 100 to 200 millimeters, with less rain falling closer to the coast. The area is very dry and temperatures often rise to 125 degrees Fahrenheit or 50 degrees Celsius. This region is the hottest place known to man. It is mostly inhabited by the Afar people who are mostly nomadic animal herders.
The Eritrean Danakil Depression biome is characterized as a desert scrubland. Vegetation is mostly confined to drought-resistant plants such as small trees, shrubs, and grasses. Wildlife in the area includes spotted hyena, black-backed jackal, squirrel, rock hyrax, Abyssinian hare, Hamadryas baboon, common warthog, Soemmering’s gazelle, Dorcas gazelle, and the last viable population of African wild ass. Birds include the ostrich, the endemic Archer’s lark, the Secretary bird, Arabian and Kori bustards, Abyssinian Roller and Crested Francolin.
At this time, there are two active research projects at the Eritrean Danakil Depression. These include the Engel Ela- Ramud project and the Buia Project. The Engel Ela- Ramud basin, as part of the extended African Rift valley, has been home to our human-related ancestors. This geological time frame is indispensable in understanding our human evolution in Africa. To date, this site gives the oldest known evidence related to our human ancestors in the Eritrean soil. This area is important in understanding the evolution of the African ecosystems during the Pliocene and Pleistocene times.
In Eritrea, the first ever evidence related to our direct ancestors is coming from the sites of Buia Basin in the Northern Red Sea Zone, about 31 km far from the Gulf of Zula. The Eritrean Danakil Depression, which is part of the vast depression of the Danakil located at the intersection of the Red Sea, the Gulf of Aden and the East African Rifts, was home to our human ancestors and different animals that date back to about 1.0 million years.
During a time of dramatic climate change, modern humans (Homo sapiens) evolved in Africa. Like early humans, modern humans gathered and hunted food. They evolved behaviors that helped them respond to the challenges of survival.
The first modern humans shared the planet with at least three species of early humans. Over time, as modern humans spread around the world, the other three species became extinct. We became the sole survivors in the human family tree.
In Eritrea, evidence of modern Humans (Homo sapiens) is found in the Red Sea coast, mainly the Gulf of Zula area. Several sites from the coastal areas of the Red Sea revealed evidence of technological tools that belonged to Modern Humans. Among these, the sites of Abdur, Asfet, and the greater Gelàlo area are the most known sites at the Buri peninsula. These sites are dated between 125, 000 to 10,000 years. The majority of these sites have evidence of Middle and Late Stone Age stone tools in association with a variety of shells. These stone tools and marine shells relate to the lifestyle and food exploitation process of Homo species thousands of years back along the coast of the Red Sea.
Modern humans conquered a wide palaeoecological landscape, preferring the coastline of the Red Sea 125, 000 years ago. They adapted to survive on the coast of the Red Sea with marine-life forming a major part of their diet.
These coastal habitats played a major role in understanding the sustainability of the human evolution, the sedentary life and the dispersal of humans.
Today, thanks to the evidences from these sites, we are able to understand that our ancestors lived in this region of our land millions of years back and their evidence is well documented on the continental and coastal landscapes of the extended Danakil Depression.