This image provided by the Institute of Tibetan Plateau Research (ITP), Chinese Academy of Sciences, shows an artistic rendering of ancient human migration. (ITP/Handout via Xinhua)

The migration and spread of ancient humans across the Eurasian continent after leaving Africa were significantly influenced by climate change and landscape evolution, according to a new study published in the journal Nature Communications.

The study, led by researchers from the Institute of Tibetan Plateau Research, Chinese Academy of Sciences, has revealed new evidence that early human migration and the development of stone tool technology in Eurasia were closely related to climate and landscape changes.

The research indicates that between 900,000 and 600,000 years ago, aridification and landscape shifts in Eurasia prompted ancient human migration and the advancement of stone tool technology in the region.

Scholars have posited that early modern human migration from Africa to East Asia followed two primary routes: the northern route and the southern route. The southern route passed through the Arabian Peninsula, India, Southeast Asia, and other regions, while the northern route traversed Central Asia, Siberia, and Northwest China.

The migration and spread of ancient humans were closely linked to the evolution of climate and environment, said Zan Jinbo, the first author and co-corresponding author of the research, and a researcher at the Institute of Tibetan Plateau Research.

Previous understanding of the relationship between ancient human diffusion and the natural environment in Eurasia was limited due to a lack of comprehensive comparison of archaeological and paleoenvironmental records over large spatial and long temporal scales, Zan said.

In this latest research, scientists analyzed the changes in the isotopic composition of organic carbon in two typical loess profiles in central Eurasia over the past 3.6 million years.

By integrating data on carbon isotopes, river terrace landscapes, distribution of aeolian loess, and ancient human remains across Eurasia, they found that since 900,000 to 600,000 years ago, global cooling and the uplift of the northern Qinghai-Xizang Plateau led to increased climate fluctuations, environmental drying, and widespread development of river terraces in the northern route region.

"There are significant differences in the environmental drivers of ancient human diffusion between Eurasia and Africa," said co-author Fang Xiaomin from the Institute of Tibetan Plateau Research, who is also an academician of the Chinese Academy of Sciences.

In North and East Africa, wet climates provided a green corridor for ancient humans to migrate out of Africa. In contrast, in Eurasia, aridification and landscape changes offered more open habitats, convenient passages, and water sources, significantly impacting the living environment and spatial diffusion of ancient humans in Eurasia, Fang said. (Xinhua)