Central Asia identified as a significant region for human ancestors: Research

Cleveland [US], October 24 : A recent study led by Dr Emma Finestone, assistant curator of human origins at the Cleveland Museum of Natural History and research affiliate of the Max Planck Institute for the Science of Human History, identified the interior of Central Asia as a crucial route for some of the earliest hominin migrations across Asia.
The results of the study suggest that Central Asia's steppe, semi-arid, and desert regions formerly provided suitable conditions for hominins' dispersion across Eurasia.
A multidisciplinary team of researchers from universities on four continents set out to increase our understanding of early human activity in the Central Asian lowlands. Dr Paul Breeze and Professor Nick Drake of Kings College London, Professor Sebastian Breitenbach of Northumbria University in Newcastle, Professor Farhod Maksudov of the Uzbekistan Academy of Sciences, and Professor Michael Petraglia of Griffith University in Queensland, Australia were all members of the team.
"Central Asia connects several zones that played important roles in hominin dispersals out of Africa and through Asia," Dr Finestone said. "Yet we know comparatively little about the early occupation of Central Asia. Most of the archaeological material is not dated and detailed paleoclimate records are scarce, making it difficult to understand early hominin dispersal and occupation dynamics in that region."
The researchers collected and examined paleoclimatic and archaeological data from Pleistocene Central Asia (about 2.58 million to 11,700 years ago). As part of this, a dataset of Paleolithic stone tools was compiled, and a stalagmite from southern Uzbekistan was examined. The ability of humans to migrate to new areas and overcome environmental problems depends on their ability to make and modify tools. As early hominins dispersed, they carried their tools with them. The stalagmite was growing at the end of Marine Isotope Stage 11, which was a mild era between glacials MIS 12 and MIS 10, about 400,000 years ago. The researchers looked at the position of stone tools and the environmental circumstances that were reflected in the stalagmite.
According to Dr Maksudov of the Uzbekistan Academy of Sciences, the majority of Lower Paleolithic (the earliest subdivision of Paleolithic stone tools) occurrences in Central Asia lack trustworthy context for dating and environmental reconstruction, so little is known about the area's earliest toolmakers.
"Despite the potential importance of Central Asia to early dispersals, our knowledge of the Lower Paleolithic across this vast and diverse landscape has been limited."
"We compiled data on Paleolithic findings from across Central Asia, creating a dataset of 132 Paleolithic sites - the largest dataset of its kind," said Professor Petraglia, a senior author on the study. "This allowed us to consider the distribution of these sites in the context of a new high-resolution speleothem-based multi-proxy record of hydrological changes in southern Uzbekistan from the Middle Pleistocene."
"Cave deposits are incredible archives of environmental conditions during their growth. Using geochemical data from stalagmites we gain insights into seasonal to millennial-scale changes in moisture availability and the climatic dynamics that governed rain- and snowfall. Our work suggests that the local and regional conditions did not follow simple long-term trends but were quite variable." said Professor Breitenbach, who led the stalagmite-based analysis.
"We argue that Central Asia was a favourable habitat for Paleolithic toolmakers when warm interglacial phases coincided with periods when the Caspian Sea was experiencing consistently high water levels, resulting in greater moisture availability and more temperate conditions in otherwise arid regions," said Dr Finestone. "The patterning of stone tool assemblages also supports this."
Lower Paleolithic toolmakers who produced bifaces may have frequented the area of arid Central Asia during sporadic warmer and wetter intervals, making it an ideal habitat (stone tools that have been worked on both sides).
"Interdisciplinary work that bridges archaeology with paleoclimate models is becoming increasingly necessary for understanding human origins," said Dr Finestone. "In the future, the databases generated in this study will continue to allow us to ask questions about the context of hominin dispersals."