In a time where ’climate change’ is a common phrase, we are looking toward a dismal future and mass extinction. How does this sort of thing happen?
The mystery of the role of people and climate in the fate of Australian megafauna might have been solved in a breakthrough study published yesterday.
‘Megafauna’, giant beasts that once roamed the continent — including wombat-like creatures as big as cars, birds more than two metres tall, and lizards more than seven metres long — became extinct about 42,000 years ago. But the role of people in their demise has been hotly debated for decades.
The new study, led by a team of researchers from the ARC Centre of Excellence for Australian Biodiversity and Heritage (CABAH), analysed fossil data, climate reconstructions, and archaeological information describing patterns in human migration across south-eastern Australia.
For the first time, the research suggests a combination of climate change and the impact of people sealed the fate of megafauna, at least in south-eastern Australia. And that distribution of freshwater — a precious commodity for animals and people alike as the climate warmed — can explain regional differences in the timing at which megafauna died out.
‘There has been much debate among scientists about what conditions led to this extinction event,’ said lead author Dr Frédérik Saltré, Research Fellow and Coordinator of the Global Ecology Lab at Flinders University.
‘Resolving this question is important because it is one of the oldest such extinction events anywhere after modern human beings evolved and left Africa’, he added.
The findings, published in Nature Communications, are the result of analysis and complex modelling based on data including more than 10,000 fossils and archaeological records.
‘The regional patterns in extinction are best explained by the hypothesis that people migrated across Australia, exploiting lakes and other sources of drinking water connecting the drier regions in between,” said co-investigator Professor Corey Bradshaw of the Global Ecology Lab at Flinders University.