Showing posts with label Human Migration. Show all posts
Showing posts with label Human Migration. Show all posts

Monday, July 23, 2018

When and Why Did Our Human Ancestors First Leave Africa?

human migration

Human Migration

Scientists are still trying to find out the earliest signs of human migration. Earlier, they discovered1.85million-year-old fossils and tools in Dmanisi, Georgia which is about 3,800 miles to the west of the new excavation site. Lately, they have uncovered tools in China which pushes back the date of human existence outside Africa to about 250, 000 years.

According to some exciting news that was published in the journal, Nature, there were scattered remains of stone tools dating back to 2.1 million years that were unearthed in Loess Plateau in China. Scientists have been tracking the human migration outside Africa. With the latest discovery, they have come closer to understanding the migration of humans from Africa more than 6 million years ago.

An anthropology and geological sciences professor, John Kappelman from the University of Texas at Austin, wrote an article in the journal Nature’s “News & Views” on the importance of such a discovery. The latest findings bridge the gap between the beginning of humans and where they are today.

Human migration from Africa


John Kappelman who was not involved with the study, shares his views about the research.

Firstly, the human migration out of Africa keeps getting pushed back in time. It is possible that the human migration was towards Asia in the east and only many years later to Europe in the west. This is substantiated with the latest discovery.

Secondly, the human migration to the north suggests that they were able to adapt to colder regions. When it became much colder, the people migrated to the south to warmer climates.

What are the reasons for human migration? 


Those who are hunter-gatherers migrate to places where resources are available. This human migration is also seen in industrial societies, where people move to areas where jobs are available. If we consider the hunter-gatherers of today, they could cover around 5-15 kms per day. If the ancient group covered that distance in a year, and the distance between China and East Africa which is 14,000 km is divided by 15 kms, then the human migration would take place within 1,000 years.

Climatic conditions during human migration


The humans migrated out of Africa during the glacial and interglacial conditions of Pliocene and Pleistocene. It is more likely they migrated during the warmer climates. The climatic conditions were equitable as compared to the extreme climates witnessed in the past million or half a million years ago.

What was the population size of China 2.1 million years ago? 


The stone tools that were discovered were scattered and not really a dense accumulation. This shows the hominin presence but the size of the population cannot be determined.

Of what materials were the tools? 


According to evidence, the raw materials were from the Qinling Mountains about 10 km away. Since there was not much excavations carried out, it is not sure if the tools came from that area itself or it was brought in during human migration.

What more are the researchers looking for? 


There were animal bones found in the sediments near some of the stone tools. They will be examining them for cut marks to see if the tools were used to process the animal carcasses for their meat and bone marrow. They can also analyse the cutting edges of the stone tools for biological residues. The team may carry out a search for human fossils. It is highly probable that some large- scale excavation may take place.