LITERARY REVIEW

Intro: A history of Earth suggests humanity will eventually perish – but new life forms will rapidly evolve to take our place

IF you were to dig deep below contemporary London gravel you would find among the clay astonishing fossilised remains of crocodiles, sea turtles and early relatives of horses.

They lived and frequented the earth in an era when London was “forests of mangrove palm and pawpaw, and waters rich in seagrass and giant lily pads, a warm, tropical paradise”.

More recently there was a time when, instead of carved stone lions built on plinths looking at people, real lions lived in what is now Trafalgar Square, gazing down on herds of elephants and hippos grazing beside a wide and meandering river.

This somewhat mind-boggling scene introduces us to the concept of “deep time”, explains Thomas Halliday, as he leads the reader on a mesmerising journey into those vast stretches of Earth’s pre-history that lie behind us. He does so on such a scale that you experience a kind of temporal vertigo just thinking about it.

Halliday is a Fellow in Earth Sciences at Birmingham University, but he is also a brilliant writer. His lyrical style vividly conjures a myriad of lost worlds from the patchy but sometimes startling fossil records. Each chapter takes us further back in time, to an older and more alien earth with every passing epoch.

It begins a mere 20,000 years ago, in the heart of the last Ice Age, and on the dry plains of Alaska: the eastern end of the awesome Mammoth Steppe, an unspoilt grassland that stretched all the way from the Americas across Russia to Ireland (sea levels being much lower then).

Over those plains roamed vast herds of herbivores: camels, bison, horses and mammoths. Camels were originally American which later migrated to the Old World over the Bering Strait.

The last mammoths survived until just 4,500 years ago, contemporaries of the Pyramids and Stonehenge, a small and increasingly inbred group on Wrangel Island near Russia.

Top predator of the Steppe was unquestionably the short-faced bear, which on its hind legs towered a metre above the three-metre-high shoulder of a mammoth.

But there were also humans around. We know this from “the footprints of a gleeful group of children, running through the ditchgrass into the mud of a chalky lakeshore, 22,500 years before the present,” and still visible “in the white sands of New Mexico”.

Imagine, then, what stories they must have told each other by the evening fire, sharing their landscape and territory with creatures including mammoths and short-faced bears.

APOCALYPTIC

By chapter three, we have dived back 5.33 million years to a truly apocalyptic moment. Then, the Mediterranean was sealed off from the Atlantic by a land bridge at Gibraltar, joining Africa to Europe.

The inland sea had evaporated, so where the Med now sparkles there was only a huge dried-out salt lake, in some places 4 kilometres below sea level, with temperatures down there reaching 80C – some 25C warmer than anything ever recorded even in the hotspots of California.

This burning saline desert was dotted with cooler volcanic island plateaus covered in cedar trees, and “a shrubland of pistachio, box, stooping carobs and gnarled olives”.

One day, a trickle of Atlantic sea-water began to seep over the top of the Gibraltar land-bridge, eroding the dry earth as it went, until the trickle became a stream, then a river – then an unstoppable cascade.

A mile high and several miles wide, the torrent roared over and dropped at 100 miles per hour, throwing up a “tumultuous cloud mist”, with the eastern Mediterranean becoming a sea once more in just one astonishing year.

Sicily and Malta became islands in that sea, populated by hippos, dwarf elephants and the Terrible Moon-Rat.

There are so many wonders here: a rock wall in modern Bolivia where dinosaur footprints climb gecko-like up a sheer vertical cliff, because the surface of the earth has tilted 90 degrees over 32 million years; beavers and hedgehogs, Asian arrivals, wiping out native European primates; the incredible fact that it was on huge rafts of vegetation riding the ocean currents that many animals, including monkeys and guinea pigs, travelled accidentally from Africa to South America, surviving an ocean voyage of at least six weeks on their uncertain craft.

Going back 550 million years ago, our world seems like another planet altogether.

Then there were animals so strange that scientists have named them Hallucigenia, and there was no North Star in the sky, nor a single star of the seven in Orion, nor brilliant Sirius. None of these familiar stars had even been born yet.

Journeying into the abysses of deep time in Otherlands will certainly make the reader feel very small and transient – a feeling both humbling and comforting – and surely reminds us that we pay too much attention to many of our own minor daily troubles.

Barring some miraculous and unprecedented effort of global cooperation, which seems rather unlikely at present, the world will rapidly head back soon to something like the swampy Eocene epoch of 50 million years ago, bringing a mass extinction of today’s flora and fauna (including us, unfortunately), and then, after a few more million years, a huge explosion of unimaginable new biological species better suited to this hothouse earth.

As the book’s subtitle aptly reminds us, this planet is still “a world in the making”.

Otherlands is a carefully and skilful choreograph of the earth’s evolution and has a very good chance of being shortlisted for Book of the Year. It is a stunning and exquisite narrative and the author deserves huge acclaim for it.