Here are some facts. Before their extinction the Denisovans were around as much as 750,000 years. This was enough time for them to develop their own unique physiology, mindset and material culture.

The earliest known modern humans existed around 300,000 years ago.

We started leaving Africa in waves perhaps as early as 200,000 years ago (maybe even earlier).

We officially reached Australia 60,000 years ago.

Genetic science tells us right now that first contact with Denisovans was around 45,000-55,000 years ago. It was almost certainly much earlier still.

Already by this time they were much more advanced than us, producing jewellery like the fabulous Denisovan bracelet.

We were the new kids on the block at this time. Yet we interbred with the Denisovans (as we had already done with the Neanderthals) and carried their legacy eastwards and southwards into the farthest reaches of the Asian continent. So the Denisovan legacy lived on, through us.

However, we also know that human fossil remains older than 100,000 years ago have turned up in China. These might now suggest a multi-regional solution to human evolution. This is possible.

However, by far the greatest influence on everything stated here is the eastward migration of early modern human populations. It was like an ocean tide carrying Denisovan ancestry to the farthest and most isolated areas of human occupation, such as Australia and Melanesia (ancient Sahul), as well as islands in the South Pacific and even the American continent.

The picture is every expanding.

We are still putting the whole thing together.