What is the oldest argument in Australian science? The argument about what caused the extinction of the Pleistocene megafauna, including the giant kangaroos and marsupial Tapirs, and the uber-echidnas, is probably the oldest in Australian science.
Sir Richard Owen, an English anatomist, suggest in 1877 that big animals driven extinct by the hostile agency of man. This means that hunting was responsible for the extermination of these large animals, a process now known as overkill. Others suggested that climate change was the reason, and it was.
Owen’s view has been support by a series of studies in a variety of disciplines, including geochronology and palaeoecology. The argument does not stop there. But why?
Many Australian archaeologists are against overkill. They’ve search for direct evidence that megafauna kill, but they haven’t found it. There are no large piles of bones in ancient campsites, no diprotodon skulls with spears embedded in their ribs and no arsenal of specialized weapons to bring down large prey. There are very few archaeological sites that have megafauna and human remains in close proximity.
Reality For Some Archaeologists Extinction
Megafauna-hunting was not a reality for some archaeologists. This conclusion is often stated with such confidence that it dismisses any non-archaeological evidence as overkill.
They haven’t asked the crucial question: If megafauna were hunt to extinction by humans, how much evidence should we be able now to find from archaeological sites? According to a new paper, archaeologists Todd Surovell (Brigid Grund) suggest that the answer is either very little or none.
Surovell & Grund first point out that the time period in which archaeological evidence could have found of megafauna being killed is only a fraction of Australia’s total archaeological record. Between 50,000 and 40,000 year ago, people arrived in Australia. This is also when animals such as diprotodon disappeared. Comparing fossil and archaeological dates shows that humans and megafauna spanned only about 4,000 years across continents. Modelling suggests that if there was an extinction due to hunting, it would have occurred in less than 1,000 years.
This means that less than 8% of the Australian archaeological records covers the period of human megafauna interaction. Overkill evidence should be rare, so it is not a smoking gun. Surovell & Grund demonstrate that finding such evidence can be even more difficult than it seems, and for two reasons.
First, the first people to arrive were very few. Therefore, living sites found at low density. Site density increased exponentially as the population grew. The earliest sites are therefore more rare than the later ones.
If megafauna were to have become extinct, the population of megafauna could have declined as people grew. As the number of sites grew, the percentage of them that could have held evidence of megafauna killings was also falling. Sites that could preserve this evidence make up a small percentage of the total archaeological record, possibly less than.01%.
Second, archaeological material is subject to erosion and weathering, and can also broken down and weather. Old sites eventually get bury beneath sediments. It is less likely that archaeological sites can found from Australia’s earliest occupation. Also, most of their contents will have vanished.
The earliest archaeological sites in Australia often only have a handful of stone tools. These tools can only tell us very little about the interaction of the first Australians and any other animals or plants.