Tasmanian megafauna extinctions linked to humans
A team of Australian and New Zealand researchers have discovered fresh evidence that could finally unravel the mystery of what killed Tasmania’s giant marsupials over 40,000 years ago.
Analysis carried out at the Australian Nuclear Science and Technology Organisation (ANSTO) on the skeletal remains of extinct megafauna is providing substantial proof that for about 2,000 years they infact shared the island with early humans before suddenly disappearing some time before the last ice age.
The findings challenge for the first real time history’s version of events and by now placing our ancestors in Tasmania at the same time as large prehistoric animals, like the Protemnodon anak (a giant wallaby), raises the chances we were involved in their extinction.The climate change debate
Popular belief has centred on three likely scenarios for the mass extinction of the megafauna in the region: environmental causes related to climate change, which was considered the key cause of their extinction. Hyper-disease and human hunting have been a distant second in the debate.
Geological work on sea level change suggests humans could not have crossed Bass Strait until around 43,000 years ago when the island was temporarily connected by a land bridge to Australia. The vanishing of megafauna was thought to have occurred thousands of years preceding human arrival, clearing them from any involvement.
That is, of course, until now.
Closing the gap between humans and megafauna
Using a technique called radiocarbon dating and a rethink on what samples are used, scientists carrying out the investigative work at Lucas Heights came up with a new set of theories.
Radiocarbon dating uses the amount of Carbon 14 available in living creatures as a measuring stick. Comparing the amount of C14 in a dead organism to available levels in the atmosphere, produces an estimate of when that organism died.
For this analysis, the team decided to carbon date protein samples found in the bones of their subjects, which were prehistoric relatives of the kangaroo, wombat and Tasmanian Devil, using the STAR and ANTARES research accelerators located at ANSTO. Continue reading, source: ANSTO [May 28, 2012]