Early hominine became extinct due to climate change

An international team of researchers, including VU Earth scientist Didier Roche, made a climate reconstruction in Southeast Africa. It seems that one of the early hominins, a specialized herbivore, has died out due to increasing drought.

07/10/2018 | 11:36 AM

The reconstruction of the hydroclimate (the interactions between water and climate) in south-eastern Africa for the past 2.14 million years is presented in Nature this week. The authors suggest the changes that took place could have had a role in early human evolution, particularly in the extinction of Paranthropus robustus.

Changes in eastern African climate over the past 2 million years are poorly understood, despite their assumed role in early human evolution. The only long-term records, which come from Lake Malawi in tropical south-eastern Africa, reveal a trend towards a progressively wetter climate over the past 1.3 million years.

Limpopo
Using a marine sediment core from offshore of the Limpopo River in south-eastern Africa, first author Thibault Caley and colleagues reconstructed the hydrological changes in the Limpopo catchment, together with a sea surface temperature record of the south-western Indian Ocean, for the past 2.14 million years.

The authors found that there was a long-term trend towards more arid conditions in south-eastern Africa between approximately 1 million and 0.6 million years ago, which contrasts with the changes seen in the record at Lake Malawi. The findings suggest that there was a gradual contraction of the rain belt towards the equator in response to increased Antarctic ice volume.
 
Herbivore
The authors speculate that the increasing drought in South Africa had consequences for the habitat of the then living hominins, especially for Paranthropus robustus. This hominine, an extinct branch in the human family tree, was a specialized herbivore. The now reconstructed climate change makes it understandable that this plant eater is extinct.