Earlier studies claimed that people did not live in Arabia until 10,000 to 11,000 years ago during the development of agriculture. However, a study published on May 5 in the journal Scientific Reports says that humans already arrived in clusters in Southern Arabia 20,000 years ago, seeking refuge from the Ice Age that made the Earth nearly unsuitable to support life.

South Arabia is an ancient region that consists of the southern region of the Arabian Peninsula, largely cantered in an area now known as the Republic of Yemen. The research team from the University of Huddersfield says that people most likely settled first on the Red Sea plains before spreading and populating the rest of Arabia and the Horn of Africa.

The researchers analysed a rare mitochondrial DNA lineage called R0a. R0a is unique to people from Arabia and the Horn of Africa.

Southern Arabia

The purple region indicates the density of human population in Arabia and Hook of Africa. Credit: University of Huddersfield

They concluded that the lineage is actually older than what experts previously believed. The findings also suggest that there was at least one refugium during the Pleistocene period, which lasted 2,588,000 to 11,700 years ago, spanning the Ice Age.

Additionally, the research team also believes that people with the R0a lineage moved through the Middle East and into Europe. They speculate that there could have been a trading network and genetic migration, also known as gene flow, from Arabia into places we now know as India, Pakistan, and Iran.

Ice Age is a glacial episode that could have been caused by massive tectonic collisions that happened near the Earth’s equator tens of millions of years ago, according to geologists at the Massachusetts Institute of Technology (MIT). The tectonic collisions exposed the rocks that were capable of absorbing carbon dioxide from the atmosphere and also concealed the volcanoes that were responsible for releasing harmful greenhouse gases like carbon dioxide, increasing global temperature subsequently.