Research at the University of Liverpool has found that periods of rapid fluctuation in temperature coincided with the emergence of the first distant relatives of human beings and the appearance and spread of stone tools.

Dr Matt Grove from the School of Archaeology, Classics and Egyptology reconstructed likely responses of human ancestors to the climate of the past five million years using genetic modelling techniques. When results were mapped against the timeline of human evolution, Dr Grove found that key events coincided with periods of high variability in recorded temperatures.

Dr Grove said: ‘The study confirmed that a major human adaptive radiation – a pattern whereby the number of coexisting species increases rapidly before crashing again to near previous levels – coincided with an extended period of climatic fluctuation. Following the onset of high climatic variability around 2.7 million years ago a number of new species appear in the fossil record, with most disappearing by 1.5 million years ago. The first stone tools appear at around 2.6 million years ago, and doubtless assisted some of these species in responding to the rapidly changing climatic conditions.

‘By 1.5 million years ago we are left with a single human ancestor – Homo erectus. The key […]