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General · 9th February 2016
Ray Grigg
Perhaps the present mass extinction of species caused by us would be more tolerable if it were unusual. Such an exception would give us excuses and a sense that the changes we need to make will be superficial and easy. The actual fault, we would like to believe, is our economic system, our consumer culture, our sophisticated technology, our exploded population. Unfortunately, history suggests otherwise — that we are serial killers, and have always been. So the changes we need to make will be much more fundamental and extensive.

After Africa, a useful place to begin examining this history, is Australia. Until Homo sapiens arrived there about 45,000 years ago, the continent had been ecologically stable for eons, escaping the ravages of serious climate changes and the cycles of ice ages. It was a continent, described by Yuval Noah Harari in Sapiens: A Brief History of Humankind, as teeming with biological diversity, including many large animals that weighed more than 200 kilograms.

These animals included an unusual marsupial lion, “as massive as a modern tiger”, huge koalas and a “giant diprotodon, a two-and-a-half ton wombat”. Other large creatures included massive “flightless birds twice the size of ostriches” and “dragon-like lizards and snakes five metres long”.

“Within a few thousand years,” writes Harari, “virtually all these giants vanished. Of the 24 animal species weighing 50 kilograms or more, 23 became extinct. A large number of smaller species also disappeared. Food chains throughout the entire Australian ecosystem were broken and rearranged. It was the most important transformation of the Australian ecosystem for millions of years.”

This 90% extinction of megafauna was more than coincidence. Nothing but the arrival of Sapiens explains such a sudden and extensive species loss. Sophisticated hunting strategies together with “fire agriculture” — the burning of huge areas to improve hunting — radically changed vegetation and the viability of species. The circumstantial evidence for Sapiens' guilt is compounded by being repeated innumerable times wherever the species arrived — within about two centuries of arriving in New Zealand 800 years ago, the Maoris had eliminated most megafauna and 60% of all birds.

The Australian experience was repeated in North America about 16,000 years ago when Sapiens crossed through Siberia and Alaska to a new continent. On their way south to Tierra del Fuego, they met and decimated populations of “mammoths, mastodons, rhinoceroses and reindeer.” Within 2,000 years of their arrival, Sapiens had eliminated “rodents the size of bears, herds of horses and camels, oversized lions and dozens of large species the like of which are completely unknown today, among them fearsome sabre-tooth cats and giant ground sloths that weighed up to eight tons and reached a height of six metres.”

Such slaughter was repeated routinely elsewhere; on Madagascar, throughout Indonesia and the islands of the Pacific, Mediterranean and Caribbean. And this was just the so-called First Wave of extinctions. The following Second Wave was caused by the Agriculture Revolution. The Third Wave, now unfolding, is predicted to render about a third of all remaining animals and plants extinct by 2100.

The designation of serial killers seems to be a harsh judgment to place on ourselves. But the evidence is incriminating.