Researchers are looking back at the past to determine how climate change has affected species in other eras, as our world heats up. New research has shown that there have been several human migrations to Arabia in the past 400,000 years.
The same type of climate shift that drove these migrations was the increase in rainfall on the Arabian Peninsula, which connects Africa to Eurasia. At least five phases of migration were likely to be caused by climate change. Hominids started to travel outside of Africa.
Archaeologists found animal fossils and stone tools in excavations of ancient lakes in the Nefud Desert, northern Saudi Arabia.
They were able to reveal previous patterns of migration over hundreds of thousands of year after being dated.
A stone tool that dates back to 400,000 years. (Palaeodeserts Project/Ian Cartwright).
Huw Groucutt from the Max Planck Institute for the Science of Human History, Germany, says that Arabia was long considered an empty space.
"Our research shows that so much remains to be known about human evolution in large areas of the globe, and it highlights the fact that there are many surprising results."
(Palaeodeserts Project/Klint Januaryulis)
Above: A severe storm strikes during excavations of an ancient lake in northern Saudi Arabia.
Some of the artifacts recovered represent the oldest known hominin occupation in Arabia. The migrations can be divided into two groups: those with an earlier Acheulean technology (like simple, hand axes), and those with a later Middle Palaeolithic tech (more sophisticated axes and more cleavers).
These migratory bursts are at 400, 300 and 200. They occurred when the Arabian desert was transformed by more frequent rainfall into more hospitable grasslands.
Luminescence dating is a method that uses light to stimulate small grains of sediment to work out when they last saw sunlight. It was used to track movement over time and mark periods.
The researchers wrote in a published paper that "the available record emphasizes pulsed long-range terrestrial dispersals followed closely by local variation and finally population contraction."
According to the researchers, what they have discovered suggests that Arabia was colonized in part by a variety of hominins. This could also be evidence of how climate change can push people into different areas of the globe.
(Palaeodeserts Project/Michael Petraglia).
Above: Khall Amayshan 4 is located in northern Saudi Arabia. It contains evidence of early human visits over the past 400,000 years, and also includes the remains of ancient lakes.
Arabia's dispersal over the past 400,000 years seems like a matter for opportunity. Communities noticed changes in the environment and moved accordingly.
It was only 10 years ago that much of the information about the Arabian Peninsula's history beyond the past ten thousands years was available. But this new study expands the already growing number of records.
"It was remarkable: people were there every time it got wet," said Michael Petraglia, archaeologist at the Max Planck Institute for the Science of Human History.
"This work places Arabia on the global map of human prehistory."
Nature published the research.
