There are several theories about how humans spread across the planet from their origins in Africa. This is thought to have happened early on, with humans travelling on foot. Findings of skeletal remnants have been found that put humans in Asia after travelling from Africa. Arabia has been thought to have been an area that humans travelled through on their way to Asia. A recent finding of finger bones at Al Wusta in Saudi Arabia’s Nefud desert shows the possibility of human existence in the area very early on.
There is a narrow strip of land that joins Africa with Asia. This part of the Middle East is where the bone was found. The desert landscape of today may make the area uninhabitable, reducing people’s ability to support the idea of humans travelling through successfully. There is, however, geologic evidence that this area of Al Wusta was once a wet area. This addition of water to the picture, adds to the possibility of its ability to support human life.
The bones found are definitely human and from the hand. They are, most likely, from the middle finger of an adult. Bones from this area of the body are usually not used for sexing specimens. It is, therefore, unclear whether or not the bones originated in a male or female. It is also not possible to tell if the bones are from the right or left hand. The bones have been compared to present day humans, monkeys, and apes. They have also been compared to various ancient hominids and Neandertals.
Scientists used a method to date the bones that measures the decay of radioactive material in the specimen. This method relies on the measurement of a form of uranium. They also compared the bone to other surrounding materials. In this case, they used a hippo tooth to gain an idea of the amount of radiation that should be expected. Exposure to natural amounts of uranium was taken into consideration. The burial of the bones in sediment also gives some idea of the time frame from which they came. Scientists dated the skeletal material at about 95,000 to 86,000 years ago. This time frame is near the time when researchers think that humans departed Africa in search of other areas. The dating that scientists use puts humans in Israel about 194,000 years ago. The presence of humans in Asia is thought to have occurred around 80,000 years ago. Indonesia and Asia are thought to have hosted humans about 60,000 years ago. These are scientific estimates.
While no other human bones were found in the same area yet, other human items have been located. The area of Al Wusta has been extensively excavated, and many tools that humans may have used were found. About 380 stone tools were found and dated to the same era. Animal fossils were also uncovered and reached a number of 860. Hippos and gazelles are two of the animals thought to be a part of the early history of the area. They are not present in the area anymore. It is theorized that climate change caused desert areas to become lush environments. The addition of lakes, rivers, and grasslands made the perfect grazing environment for animals that humans used for food. This meant that hunter-gatherers needed to follow the animals to have a steady food source. The areas possibly dried out over time, leaving humans with the option of following the animals back to Africa, or moving on to Asia.
It has also been thought that humans may have left Africa in large migration groups. Recent findings challenge these early theories. The finger bone fossil at Al Wusta in combination with tools found in other sites on the Arabian Peninsula, make these theories questionable. Instead of one large migration, or a few, it is now thought that smaller groups may have travelled across the area. It is now suggested that humans regularly travelled between Africa and Asia due to changes in rainfall patterns. These rainfall patterns may have opened up various opportunities to travel in the area. There are various ideas of travel routes, as well. These include walking along the Nile River Valley, and a thin sea channel starting in the Horn of Africa.
Dispersal of humans across the world follows the theory that there was a single starting point for human existence. This is thought to have been somewhere in Africa. Travel theories have been long studied by anthropologists. Today’s landscape may not support travel in many areas, making it necessary to consider changing weather patterns of long ago. Humans are a resilient species, seeking areas of land that are likely to assist in survival.