Researchers from the Institute of Geophysics and Meteorology at the University of Cologne have developed an ‘Our Way Model’ to understand how the first anatomically modern humans colonised Europe. The results were published in Nature Communications under the title ‘Reconstruction of human dispersal during Aurignacian on pan-European scale’.

Cologne, September 04th, 2024: Scientists at the University of Cologne have developed a model to show how the first anatomically modern humans spread between 43,000 and 32,000 years ago, during the Aurignacian, the last ice age. The ‘Our Way Model’ shows in four phases how the first phase of colonisation spread slowly from the Levant to the Balkans. In a second phase, a rapid spread to Western Europe until the population declined in a third phase. The fourth phase was characterised by a regional population density. The fourth phase continued to be characterised by settlements towards Great Britain and the Iberian Peninsula.

Early anatomically modern humans survived as hunter-gatherers over extremely long periods of time. When they began to spread across Europe, climatic conditions were different worldwide than they are today: the predominantly cooler and drier climate of the last ice age was repeatedly interrupted by warmer phases, with some changes occurring abruptly and others gradually. The spread of humans to Europe was presumably due to the diverse and extensive human spirit of discovery, a changed social structure and technological progress. However, the model shows how climate change affected the spread of humans. The dispersal processes were not linear; sometimes people advanced rapidly and sometimes they retreated to climatic refuges.

The research team assumes that the early colonisation of Europe involved highly complex processes of expansion, retreat, abandonment and recolonisation, which were caused by climatic changes and the adaptability of humans.

The results of the study show that the first phase of relatively slow westward expansion from the Levant to the Balkans (ca. 45,000 to 43,250 years ago) was followed by a second phase of rapid expansion into Western Europe (ca. 43,250 to 41,000 years ago). Although interrupted by brief setbacks, Homo sapiens populations now rapidly reached an estimated 60,000 people throughout Europe, spread across all known archaeological sites of this period.

The subsequent third phase was characterised by a decline in the human population, both in terms of its size and density and the area it inhabited (around 41,000 to 39,000 years ago). This development was the result of a prolonged cold phase that lasted almost 3,000 years and is known as the GS9/HE4 phase. According to the model, however, humans survived in topographically protected favourable areas (for example in the Alps), which they had just colonised in the previous phase.

In the fourth phase, beginning around 38,000 years ago, when HEP conditions improved again, the population recovered quickly and continued to grow. The regional increase in population density and the further advance into previously unsettled areas of Britain and the Iberian Peninsula shown by the model are largely consistent with archaeological evidence.

The HEP maps show that at the end of the process, some groups were better adapted to cold climate conditions than others, which enabled them to cross the boundaries of previously colonised areas. ‘Regional studies are hardly able to capture all the factors that play a role in the reconstruction of human dispersal. This also includes the question of how the factors interact at different scales and contribute to long-term overall trends. This is a major advantage of the new modelling approach,’ says Dr Isabell Schmidt from the Institute of Prehistory and Early History.

In further research, the team will test the assumptions on which the model is based, focussing on the role of cultural development in human dispersal processes. The ‘Human and Earth System Coupled Research’ (HESCOR) project at the University of Cologne will integrate further aspects of the interactions between humans and the Earth system into the model.

Originalpublication:

https://www.nature.com/articles/s41467-024-51349-y
DOI: 10.1038/s41467-024-51349-y

Further Information:
https://hescor.uni-koeln.de

PictureSource:
Franz Bachinger Pixabay