Australasian Science: Australia's authority on science since 1938

Darwin’s Aussie Epiphany

By Peter Bowditch

Long before he struck upon his theory of natural selection, Charles Darwin experienced a revelation while exploring the Blue Mountains.

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I live about 900 metres above sea level. Beneath me are layers of sandstone, coal and shale built up over hundreds of millions of years of erosion, sedimentation and compression.

About 150 million years ago an enormous slab of this was forced upwards by tectonic forces, and this was followed by a period of volcanic activity caused by the movement, with volcanoes pouring a layer of basalt over the top. Weather, water and gravity then conspired to create great cavities in the rock formation – the valleys we see today.

The locality might be called the Blue Mountains, but really it’s a huge plateau with very big holes in it. And it’s not blue – the predominant colours are the yellows and oranges of the sandstone and the dark grey-green of gum trees. The name comes from what Darwin called “a thin blue haze” caused by vapour emitted by the billions of eucalyptus trees.

In January 1836 Charles Darwin visited the town where I live. He stayed at the Weatherboard Hotel, which was on a site now occupied by a commuter car park at Wentworth Falls railway station, and on 17 January he took a walk through the bush to the top of Wentworth Falls and looked out over the Jamison Valley. You can take the same journey today along the Charles Darwin Walk, which starts in a park and follows the path that Darwin used. (It passes a few hundred metres from my house.)


The full text of this article can be purchased from Informit.