We were hell on other species before we were even us

Homo sapiens has been driving other species into extinction for a very long time. We are familiar with more recent events on our own continent with the annihilation of species such as the passenger pigeon and, very nearly, the American bison. But it started much earlier than that. Paleontologists suspect that the disappearance of some of the larger species of North America—horses, camels, mammoths, mastodons, giant bears, and many others—was due, in part at least, to the arrival of the Clovis people 10 to 15 thousand years ago.

This pattern is repeated around the world. In Australia, many of the great marsupials vanished around 50,000 years ago, following the arrival of humans. In Madagascar, humans arrived about 2,000 years ago, after which nearly all of the island's megafauna went extinct. In New Zealand, the victims were birds. With no mammalian predators present, the islands were a bird paradise, including 11 species of flightless birds, one a giant, 12-feet tall. After Polynesian settlers arrived around 1500 AD, accompanied by dogs and rats, one fter another disappeared. Today only one is left. And so it goes, from island to island, continent to continent.

Our greatest assault on the environment began of course with the invention of intensive agriculture in Mesopotamia 5-6,000 years ago when we first began the wholesale conversion of prairie and forest into desert, a process that continues apace today.

Now, scientists suggest that we were annihilating other species long before we became Homo sapiens. In an article in the November issue of Scientific American, fossil expert Lars Werdelin explains the sharp decline of large carnivores in Africa beginning around two million years ago as due to the rise of Homo erectus. Entire groups of species, including the sabertooth cats, disappeared during this period.

Prior to this time, hominins were believed to be "relatively small-brained, chimpanzee-sized creatures that subsisted primarily on plant foods." But erectus were "bigger, smarter and armed with stone tools," and they had a hearty appetite for meat. With a rapidly evolving intelligence and social co-operation, they were serious competitors in the meat market. When game was scarce, the big predators were in trouble, but erectus could resort to plant foods to carry them through the hard times.

Our forbears had excuses for the malign affects of their behaviour—ignorance and need. They didn't understand what they were doing to their neighbours and, in any case, times were precarious. We do understand and our wants greatly exceed our needs, but we continue nonetheless to wipe out one species after another. The age of Homo sapiens is referred to by some biologists as the Sixth Major Extinction.

The Scientific American article is entitled "King of Beasts," an appropriate label. However, the king's rapacious ways have now got him into serious trouble. If we don't soon come to our senses, we may not go the way of the sabertooths, but our civilization will.