How to make sense of the global environmental changes that are taking place before our eyes? The ice is melting, species are on the move or disappearing, ecosystems are on the brink of collapse. One way is, as Thomas Halliday might say, “rockwise”: by considering the global changes that have happened all through Earth’s history, evidence for which can be found in the world’s rocks, “visiting extinct sites with the mindset of a traveller, a safari-goer”. Hallliday delivers on that promise and then some in this fascinating, enlightening and ultimately urgent safari through time.
Halliday, after a prologue in the present, begins his journey only 20,000 years ago, in the peculiarly dry steppe of Alaska amidst the ice sheets of the last ice age. Here, horses eke out a living on what stubble they can find among wind blown sand dunes, at the edge of an ecosystem, now nearly entirely gone, reaching from Alaska to western Europe, the mammoth steppe. Next we move onto Kenya 4 million years ago, where Australopithecus is starting to walk upright on the shores of vanished Lake Tomyun, while extinct bear otters chase fish. And so on, stepping back through 550 million years of life, passing by South American grasslands and Antarctic rainforests, a variety of lakes, rivers and shores (this because of the most favourable circumstances of fossilisation). Although some relatively well-known beasts stalk the pages of Otherlands, this is firmly an ensemble cast, with often overlooked supporting characters granted their turn in the spotlight: plants, insects, fungi and lichens, strange mammals and reptiles that have left no living descendants. Geological processes get plenty of look-in too; winds and waters scour the surface, while the earth’s crust shifts below.
This is also the story of how these times and places have been preserved so perfectly that the relationships between their inhabitants can be disentangled. Such sites are rare in the fossil record, and Halliday has made a selection of some of the most fascinating, such as the Hell Creek formation that preserves the post-apocalyptic colonisers of the end-of-Cretaceous meteorite, the Yixian dinosaur fossils of Cretaceous China or the jelly creatures of Ediacara in Australia, places where “even the transience of a song, a startling wing-flap, is made solid and lasting”. The past may be a foreign country, but it is frankly astounding how scientists have been able to piece together the relationships and day-to-day lives of creatures that lived hundreds of millions of years ago. Some are inferred from the traces they have left in the mud, or from their remains found in fossil dung. The advances in palaeontology are astonishing, with even colour able to be determined from preserved molecules.
Travelling backwards there is not just awe but also a kind of aching, as the familiar becomes slowly stranger. Nothing is permanent; even if you would like to linger a moment longer in a Carboniferous swamp time continues its relentless flow. It is here that Otherlands finds its urgency. Too often the work of geologists and palaeontologists has been press-ganged into doubt-mongering; the profound changes of the past evidence that the environmental changes we are seeing in our own lifetimes are nothing to worry about in the long-term. But Halliday does not pull his punches. Evidence from the past is brutally clear: the rate of change we are seeing now matches that of the periods of greatest tumult in life’s history, when whole swathes of the evolutionary tree have been felled in a geological instant. There are analogues aplenty, but particularly for the future of coral reefs. Coral reefs, Halliday shows, are a relatively rare feature on Earth, reliant on cooler, less acidic seas. In the past, reefs have been most often made by sponges or other lifeforms. Now, as the seas warm and acidify, the sponge reefs are returning. Even the graves of ancient life are being desecrated. Hallidays describes how, with some irony, fossil sites are being destroyed through coal mining or for the cooling ponds of nuclear reactors. Moreover, for the first time in life’s history, we are able to understand and predict the consequences of our actions, or lack of action.
Although Halliday steps us through the basics of ecology and palaeontology – explaining concepts like communities, ecosystems, extinction – there is a level of assumed knowledge, and certainly interest. At its best, it finds a lyricism and rhythm in these disciplines’ technical language, such as the winds blowing off an African ice cap 444 million years ago:
As the winds scour through the drumlins of this end of Africa, scraping the worn edges of the valleys bare of snow, they become dust-blowers, sweeping up the granular remains of rocks rubbed to sand, exposed as the glaciers are retreating. Earth in the sky. The pack-ice is striped with sastrugi, finely grooved ridges and waves of ice, sometimes smooth as crumpled silk, sometimes an angry churned-wave image of the trapped ocean below, surrounded by an orange corona and scattering the winter sun. The sand settles on the ice as it grows through the winter, incorporated into the freezing mixture and held in place, waiting.
This is a book that will satisfy anyone who has ever yearned to travel in time and set foot in different worlds.
Gay rating: not gay.