OPINION: Last week Liberal Democrats Senator David Leyonhjelm was widely reported as suggesting that people other than Aboriginal Australians may have occupied the Australian continent in the past.

At a doorstop at Parliament House he apparently couldn’t name his sources when pressed by journalists and seemed rather vague on the details.

His doubt was apparently based on disagreement among anthropologists over the identity of the painters of the so-called ‘Bradshaw’ or ‘Gwion Gwion’ rock paintings in the Kimberley region of Western Australia.

Now there is a very strong sense of deja vu here because this very issue was at the centre of a widely reported and politically fuelled stoush from the late 1990s to mid-2000s, but back then within the context of Native Title.

Actually, the debate over these paintings has existed ever since Joseph Bradshaw brought attention to them in 1892 because they were thought at the time to be ‘too advanced’ to have been made by Aborigines.

This fitted a 19th Century linear worldview in which societies progressed from primitive to advanced, the Bradshaw/Gwion Gwion paintings being touted as an anomaly made by an exotic people.

The Bradshaw/Gwion Gwion art style was however widely accepted by academic researchers from the late 1960s onwards as belonging within the broader rock art traditions of Northern Australia.

But following the publication of a book about the art in 1994 by amateur archaeologist Grahame Walsh the 19th Century view made a comeback.

Walsh argued that the Bradshaw/Gwion Gwion tradition was painted by a pre-Aboriginal group 20,000 years ago, Aboriginal Australians only arriving in the area 10,000 years ago.

In a second book published in 2000, he even went to great lengths to disconnect Aboriginal Australians culturally from the Bradshaw/Gwion Gwion paintings and instead connected them to a population possibly originating in Africa.

A great deal of space has been devoted in academic journals to deconstructing Walsh’s unfounded ideas and analyzing the political fallout from them.

Ian McNiven, an archaeologist at Monash University, wrote an article in 2011 in the journal Australian Archaeology about the 1990s/2000s public debate over them.

As he noted, there is very good evidence for cultural continuity between these paintings and recent art as documented for example by amateur archaeologist David Welch in 1996.

Paul Taçon who holds a chair in rock art research at Griffith University also pointed out in an article in Nature Australia (1998-1999) that Welch:

“has documented a recent use of every type of artifact depicted in Bradshaw art, strongly suggesting the paintings reflect Indigenous Australian way of life”.

More broadly, the science of human origins has moved a long way in the last two decades not the least because of big developments in genetic research.

DNA shows clearly that Aboriginal and Torres Strait Islander people are directly descended from the earliest humans to have settled Australia, New Guinea and surrounding islands.

Genetic clocks show they split from populations alive in East Asia today between 45,000 and 75,000 years ago.

Human skeletons from the Willandra Lakes region of southwest New South Wales also make abundantly clear that living Aboriginal Australians are the very same people as those who arrived here more than 40,000 years ago.

McNiven has also pointed out the very long history of the political use of archaeology to justify colonial ends by disassociating Indigenous people from their land and heritage.

He pithily concluded in 2011:

Thus, I suspect, we haven not heard the last of colonialist interpretations of Gwion Gwion paintings. As long as Australian society struggles to comprehend and acknowledge Aboriginal Native Title rights, archaeology will continue to be manipulated by those seeking to undermine Aboriginal authenticity and legitimacy of connections to land and heritage.

And so it is now with Constitutional recognition of Australia’s First people: once again Aboriginal and Torres Strait people find their history and culture being rewritten by ignorant politicians for ideological reasons.

Senator Leyonhjelm’s comments are clearly an attempt to reopen the Bradshaw/Gwion Gwion debate, and in so doing, cast doubt over the legitimacy of Aboriginal and Torres Strait Island people as the first inhabitants of Australia.

Sadly, he might just succeed within the context of a 24 hour news cycle and the seeming absence of a long term memory in the media and society more broadly.

Darren Curnoe is a human evolution specialist & ARC Future Fellow at UNSW.

This opinion piece was first published in The Conversation.