Book Review: The Sixth Extinction: An Unnatural History

Is Homo sapiens the most zealous 'overkiller' ever to have walked on the surface of Earth? Of all the species on our planet, more than 90 percent are believed to be extinct, most of them in the last half a billion years, in one of the five major mass extinction events that remarkably restructured the world we see around us. Author and New Yorker columnist Elizabeth Kolbert, in her latest book The Sixth Extinction: An Unnatural History, presents a fascinating and frightening narrative, stating humans "might not only be the agent of the sixth extinction, but also risks being one of its victims."

The Sixth Extinction
Evolution and extinction are two sides of the same coin. One leads to the other, and vice versa. Charles Darwin's famous voyage aboard the HMS Beagle paved way for a better understanding of how lifeforms began to evolve on Earth, but until then people found it real hard to accept the idea that a species that had once lived had been subsequently lost. Is there a force that's simply powerful enough to wipe out an entire species into oblivion?

Turns out, we ourselves are one big almighty force. Humans have not only become the most dominant and the most successful species, but have also turned out to be the most potent agents of change, drastically transforming and disrupting the planet's ecosystems and feedback loops, thus making it tough for other organisms to survive and cope up. Survival of the fittest is all that matters! But do we ever realize that in doing so we are pushing ourselves towards the inevitable?

Charting their history, Kolbert says, extinctions were always thought to be either sudden and catastrophic, giving no time for animals and plants to prepare, or a gradual unending and undetectable process. Georges Cuvier, the first ever naturalist to term the fossilized finds of once lived animals as "especes perdues" or lost species, was a proponent of the former school of thought, while Charles Lyell and Darwin belonged to the latter. Darwin for all his contributions, writes the author, was reluctant to accept humans' role in recent extinctions despite evidence to the contrary (a case in example is that of the great auk which was mercilessly hunted down to zilch for its meat and eggs in the mid-nineteenth century, about the same time Darwin undertook his journey to the Galapagos).

But it wasn't till the 1980's that extinctions as "sudden revolutions" began to gain footing. The father-son duo of Luis and Walter Alvarez shook up the world when they announced that the fifth major mass extinction that wiped out dinosaurs and other non-avian species in the late Cretaceous period 65 million years ago was due to an asteroid impact. More interestingly, species that learnt the tricks of survival were totally unprepared for this extraterrestrial apocalypse. If you were a dinosaur in Canada when that asteroid hit the Yucatán peninsula, you had approximately two minutes to live.

Yet, the situation that we are in the midst of is a new kind of extinction event, one that causes massive species die-off not because of long term gradual evolutionary changes or sudden cataclysms, but instead is an event precipitated by the advent of the modern thinking man. The idea of an Anthropocene driven extinction has been met with the usual scepticism, however the proof is there for all to see. In our relentless pursuit of plundering the earth's resources, we have unleashed what none of the other species managed to do, not even our ancestors - the Neanderthals, whose DNA varies from ours' by less than a minuscule 0.3 percent.

Global warming, ocean acidification, ecosystem and habitat loss, erratic weather pattern shifts, overkilling are all indeed happening, and they are happening at an unimaginable scale. And expecting fellow species to adapt so quickly to an ever-changing environment is outright absurd and meaningless. Kolbert's heart-rending portraits of the critically endangered Sumatran rhinoceros (Suci, one of the world's last Sumatran rhinos, died on March 30), brown bats, Panamian golden frogs and the coral ecosystems in Great Barrier Reef make for a disquieting read. What is so unique about man that makes him admire nature and at the same time destroy it? Is it is his intellect? Or is it his insatiable hunger for exploration and exploitation?

It's not all. As we move towards a highly interconnected world, the geographical separation notwithstanding, the "New Pangaea" also risks introducing invasive species (and new diseases) that could spell doom to host populations. When a new killer emerges, Kolbert writes, "it's like bringing a gun to a knife fight." Is this how we want our future to be? So bleak, dreary and depauperated? Like I said before, we humans are agents of change, and so let it be for the better this time around. Timely, meticulously researched and thoroughly engaging, The Sixth Extinction is a clarion call and an unflinching look at the irreversible disaster caused by us. Closing my review with one of the passages from the book:

"[Jan] Zalasiewicz [one of the key characters in the book] is convinced that even a moderately competent stratigrapher will, at the distance of a hundred million years or so, be able to tell that something extraordinary happened at the moment in time that counts for us as today. This is the case even though a hundred million years from now, all that we consider to be the great works of man—the sculptures and the libraries, the monuments and the museums, the cities and the factories—will be compressed into a layer of sediment not much thicker than a cigarette paper."

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