We've just been into Palm Valley, that delightful and impressive gorge, part of the Finke River system, south-west of Alice Springs, for the first time in years.
For something a little different we went in with Finke River Adventures in their Can-Am ATVs. They have a special licence to operate within the park and through the adjoining Aboriginal land, which sees you get off the main access road into the park. Needless to say we had a ball and it gives you a different insight into the area and the valley itself. Check them out online.
Previously when we wandered around this delightful oasis, the prevailing mantra was that the ancient palms, first discovered by Europeans when Ernest Giles stumbled on the place, were a hangover from a distant Gondwana land. Even the local government and tourist paraphernalia waxed lyrically about the red cabbage palm, Livistona mariae, stating it was a survivor from a much wetter rainforest past when Australia was connected to Africa and Antarctica.
Picture credit: TonyFeder/Getty Images & Ron and Viv Moon
Now the most recent research has blown that theory out the window; it says the palm of the Finke River is the same specie as you'll find at Mataranka in the tropics of the NT and at Lawn Hill in Queensland’s Gulf Country. More surprising is the fact that they only became separated 15,000 years ago, which is a long way short of the 100 million years proposed by the Gondwana theory.
The question now is how and why these three lots of palms, separated by 1000km or more, came to be, and if humans were involved in the long-distance dispersal. Going by the signs at the start of the walk into the valley, the jury is still actually out on how they got here. There are three theories – the old one from Gondwana land has lost cred in the last few years, so that leaves two. Maybe birds ate the fruit and then flew south and dropped the seed, which resulted in the verdant extravaganza we now have. Or, the palms were brought to this gorge sometime in the distant past by Aboriginal Australians. That seems to be the most likely scenario, but it raises the question, why only to these three very separate places?
Over in the Kimberley another tree that was once thought of as a survivor from the ancient epoch of Gondwana is the boab. These great, twisted and contorted trees are so distinctive they are hard to miss and attract many admirers – both locals and visitors. All told, there are eight species of boabs, or baobabs, in the world: six in Madagascar, one in wider Africa and one in Australia. The Australian species is most similar to the African version.
The close genetic connection between the Australian and African boabs means that there is no chance they have been separated for more than a hundred thousand years or so. Now the question is, how did our Aussie boabs arrive here?
While some researchers have looked at a transoceanic voyage of dispersal, that has now been almost universally rejected for a number of reasons, including the fact that our thin-shelled boab nuts couldn't stand such a long soaking in sea water. That has raised the possibility that the dispersal of the boab out of Africa occurred with one of the last human migrations out of that continent, which occurred between 60 and 70 thousand years ago.
Now it becomes a bit more controversial!
The distribution of boabs in northern Australia seems to relate closely to the distribution of the ancient rock art known as Bradshaw or Gwion Gwion art. While there is a lot of discussion about Bradshaw art it's almost universally agreed that it is much older than the Wandjina rock art that dominates much of the Kimberley.
When the late Grahame Walsh and others proposed the theory that Bradshaws were painted by an earlier lot of immigrants than the current Aboriginals, Walsh and his supporters were branded as 'racist'. I'm not sure why, but I'm guessing there's a lot of vested interests in that debate.
Still, if people did bring the boab to Australia about 60,000 years ago, how did they get here? The current Aboriginal people do not have the sea-going technology for such a long journey, but it seems the civilisation that painted the Bradshaws did. Walsh found, among the many galleries he discovered and researched, a number of paintings which look like large boats with up to 30 people on board.
It seems we have much to learn about where our palms, boabs and ancient peoples first came from. Whatever the answers, it probably wont please everyone!