The giant Irish deer, alas, is no longer with us. The last one, it seems, died in Russia about 7,700 years ago. Woolly mammoths, cave bears, and many less famous creatures, also went to the wall in comparatively recent times. Climate fluctuations were probably responsible for their demise. But was hunting pressure also a factor, the straw which broke the camel’s back?
In the 1960s, anthropologist Paul Martin put forward the ‘overkill hypothesis’, according to which hunting by people, newly arrived in America, had eliminated many large animal species there.
Since the days of Homo erectus, who lived around 1.5m years ago, Neanderthals Denisovans and our modern human ancestors depended on hunting and gathering for survival. Then, about 12,000 years ago, people began farming in the Middle East. Was it just a coincidence that this ‘Neolithic revolution’ took place soon after the disappearance of many large mammals? In a paper just published, researchers at the University of Tel Aviv suggest that it wasn’t.
The area between the Mediterranean and Iraq is extraordinarily rich archaeologically. Scientists have been studying ancient sites there for a century and a half. The Tel Aviv team carried out a detailed examination of the many bones and artefacts discovered during excavations at 58 locations.
Bones of 83 species hunted by archaic humans were identified. Using statistical pyrotechnics, the researchers estimated ‘the weighted mean mass of faunal assemblages through time’. The effects of temperature rainfall and environmental change were factored into the analysis.
‘Mean hunted animal masses 10,500 years ago were only 1.7% of those 1.5 million years ago’, they claim in a paper just published. Although there was a succession of ice ages and interglacials during the period, animal body sizes were not related to either global temperatures or temperature changes. However, the average size of prey animals declined steadily over time. ‘New human lineages’, the team concluded, ‘hunted significantly smaller prey than the proceeding ones’.
This suggests that, at any time, humans hunted the largest animals available and that, when a species became so rare that it was too demanding to hunt it, they went after the next largest one. Hunting equipment and methodology became more sophisticated over time to meet new challenges.
Targeting the largest animals would have provided a greater return on hunting effort in terms of meat bones and hides obtained. This, the researchers argue, led to scarcity and, in some cases, extinction of the largest species. The hunters had killed the goose that laid the golden eggs.
The authors speculate that the extinction of many prey species, and the increasing scarcity of those remaining, forced people in the Middle East to adopt a radical new survival strategy; agriculture.
The planting of crops and domestication of animals, which began around that time, would have the most profound consequences for our planet’s history.
If the Tel Aviv team’s suggestion is correct, excessive hunting spawned the agricultural revolution and ultimately the human population explosion. The consequent environmental destruction had its origins, not just in the Industrial Revolution, but ultimately in the hunting behaviour of our remote ancestors.
- Jacob Dembitzer et al. Levantine overkill: 1.5 million years of hunting down the body size distribution. Quaternary Science Reviews. 2022.