Ancient people avoided areas with malaria

We're talking about a period of about 74,000 to 5,000 years ago.

Details

The authors modelled where mosquitoes carrying Plasmodium falciparum, the most dangerous form of malaria, might have spread in ancient Africa. To do this, they used distribution models of the three major malaria mosquito complexes, ancient climate data and epidemiological information. These maps were then compared with an independent reconstruction of where humans might have lived during the same periods.

The result was quite clear: human groups, the models suggest, avoided areas with a high risk of malaria transmission or could not have stayed there for long. In contrast, areas with low and unstable transmission proved more suitable for living.

According to the researchers, this affected more than just day-to-day survival. Malaria could divide human groups across the landscape, creating distinctive "corridors" and "islands" of habitat and thereby affecting how populations met, mixed and exchanged genes. The authors explicitly link this effect to the formation of modern human population structure.

Why it matters

The study's main conclusion is that it wasn't just temperature, humidity and topography that influenced early human history. Disease, too, may have been a fundamental factor in determining where people were able to live, where they moved, and how closely they came into contact with each other.

This changes the very approach to studying ancient human settlement. Whereas previously the map of human history was mainly tried to be explained by climate, researchers are now proposing that the map of ancient diseases should also be taken into account.

Background

The authors emphasise that we are not talking about direct archaeological traces of malaria, but about model-based reconstruction. That is, the study does not "prove" the behaviour of a particular group of people, but shows a consistent relationship between the perceived risk of malaria and areas of human habitation in ancient Africa.

The work focuses on the period before the widespread spread of agriculture, when malaria transmission was not yet so heavily modified by human economic activity.

Source

The study by Margherita Colucci and co-authors is published in Science Advances; it was also announced by the Institute of Geoanthropology of the Max Planck Society.