Enough ghosts of Gondwana for a second edition

OPINION Gibbs recently published the book Ghosts of Gondwana, which explains how, when and why New Zealand inherited so many unique animals and plants from the ancient continent.

In fact, Dr Gibbs wrote an award-winning book with the same title in 2006. But because so many remarkable fossil and living organisms have been discovered around the Pacific, and because DNA discoveries have come thick and fast over the last decade, Gibbs felt bound to virtually rewrite Ghosts of Gondwana.

The second edition of Gondwana is 135 pages longer than the first edition, with many striking, large, colourful illustrations. It is written in a simple, engaging style, as though Gibbs is personally taking you by the hand through 80 million years of natural history in the remotest corners of the Southern Hemisphere.

Until recently, most speculation about our ancient evolutionary history was based on big animals such as moas, kiwis and tuatara. But Gibbs draws on his specialty – a range of lesser animals such as shrimps, crayfish, snails, freshwater mussels, moths, cicadas, alderflies, caddis flies, bat flies, mayflies and whitebait that once inhabited Gondwana.

DNA gives biologists X-ray eyes to measure the genetic distance between organisms and to accurately date every fork on the tree of life. Over the last decade or two, the DNA of innumerable animals and plants from New Zealand and the Southern Hemisphere has been read.

The readouts enabled Gibbs to build family trees of New Zealand’s fauna and flora. He explains where these organisms came from, and how they evolved into their present form, why they survive to the present day and why some biologists call New Zealand ‘‘Darwin’s south seas laboratory’’.

Along the way, Gibbs addresses a controversy that has simmered among scientists for some time: did New Zealand sink completely beneath rising sea levels about 20 million years ago, drowning all Gondwana animals and plants? Or did some small part of New Zealand remain above the high seas to maintain a Gondwanan presence?

Gibbs argues that some small islands acted as refuges for Gondwanan tuatara, land-going and freshwater insects, whitebait, koura and shrimps. Moas and kiwi probably flew to New Zealand and, with no mammalian predators, lost their power of flight here.

Years ago, New Zealand had no high mountains. They were all pushed up over the last two million years. Many lowland animals and plants spread uphill and evolved into new alpine species since then. This history accounts for an astonishing diversity of cicadas, lizards, wetas, snails, hebes, buttercups and willow herbs, now isolated on different mountain ranges.

Ghosts of Gondwana is an astonishing, elegant, compilation – a scientific and literary tour de force.

Ghosts of Gondwana,

revised edition, by George Gibbs. Potton & Burton, 2016. $59.99