The largest animals, like the woolly mammoth and rhinoceres, went extinct around the world about 10,000 years ago. The main reason the woolly mammoth is gone is that we ate them all.

House built from Mammoth bones, Mezhyrich, Ukraine

After the animals were gone for long enough, there wasn’t even a cultural memory in many places. Some later people came across fossils in confusion. The cyclops myth might have come from humans that came across tuskless mammoth skulls:

Animals like horses still lived on in Africa and Asia, but North America ended up more heavily depleted. This has to do with the history of how humans evolved and spread through the world. We’re all originally from Africa but different species of hominids left the continent at different times. A proto-human, Homo Erectus, left Africa almost 2 million years ago (yellow path, shown below). Modern Homo Sapiens continued to evolve in Africa, and migrated out 50,000 years ago (green path).

Homo Erectus migrated 2 million years ago (yellow). Homo Sapiens left Africa 50 thousand years ago (green)

Animals in Africa evolved alongside humans and learned to fear us. Animals in Europe and Asia lived alongside Homo Erectus for 1 or 2 million years, and learned to fear them. Animals in the Americas, on the other hand, first encountered humans only 15,000 years ago, after we’d become much smarter and much better at hunting. Many of these species didn’t stand a chance.

The same thing happened in Australia, 50,000 years ago. Early aborigines killed off any local animal larger than a kangaroo. The same happened in Madagascar and New Zealand, 1,500 years ago, when the first Polynesian sailers arrived on each island. Giant Lemurs quickly disappeared from Madagascar while New Zealand lost large animals like the 12 foot tall Moa bird.

We like to imagine Native Americans as a sustainable culture, living in harmony with nature. That may have been true in 1492. 13,000 years earlier, life was in flux, and very much not in balance.

This sounds like an isolated ecological catastrophe — some early people didn’t know their environmental limits and many animals went extinct. The events had a profound impact on the future of human civilizations, though.

Thousands of years later, people started to grow crops and domesticate animals, to shape the world, and create civilizations. Jared Diamond’s theory holds that each continent developed at a different rate because they had different crops to work with and animals to domesticate. The horse and cow were domesticated in Eurasia, water buffalo in India and China, pigs in the middle east and China, chickens in southeast Asia.

In North and Central America, the options weren’t as good. North Americans domesticated dogs and turkeys. In the absence of horses, dogs were sometimes used to pull loads.

Crops in North America also happened to be less useful. China had rice and the middle East had wheat. Mexico had a plant called Teosinte that Aztecs gradually bred into modern corn:

The aztecs had no useful animals to use for labor. There were no horses to ride, since they’d already been eradicated from the continent. Bison were ill-tempered and dangerous compared to cows. Neither elk, deer, moose, or bison make useful animals for riding.

Early north and central Americans didn’t use wheels. They had certainly thought of the idea — the Aztecs made toy cars but not full sized vehicles.

Maybe a wheeled carriage just isn’t as useful when you don’t have horses to pull it. The closest domestic pack animal was the Peruvian llama, but there was little transmission of technology between North and South America, where it would have to go through the jungles of Panama. Crops, animals, and technology spread better in the old world, which had trade routes stretching all the way from Europe to Asia.

After 1492, when civilizations collided, the Spaniards had armies on horseback and other devastating military technologies. They also came bringing deadly germs, some of which they carried from living in proximity with domestic animals. The Aztecs and other Native Americans were almost wiped out.

You can trace that defeat, in part, to the extinctions that happened ten thousand years prior. Had horses persisted in North America, both armies might have been riding them. Had people raised domestic animals on both continents, foreign colonists might not have been able to easily take over the Americas. No hunter in 10,000 BC possibly thought of those long-term consequences.

After Columbus, petroglyphs in Utah show a new culture. We see hunters on horseback:

Newspaper rock near Canyonlands park

We possibly see a wheel in the image (though this might have been something more symbolic, like a medicine wheel).

Native American culture evolved a bit, but European colonists rapidly took over the continent. These new Americans didn’t treat wildlife well, either:

Small mountain of Bison skulls.

Passengers on the newly built railroad would shoot bison for sport. The great plains originally supported tens of millions of bison, but by the late 1800's, only a few hundred remained. The species was preserved by a few ranchers who raised private herds for meat.

The grizzly bear was common enough in California, in 1850, to be featured on the state’s flag, but it was hunted to extinction from the state by 1922.

Grizzlies now live only in Alaska, Canada, and small pockets of 4 northern states.

Fur trappers on the west coast almost completely eliminated otter and seal populations. Elephant seals survived only because of one untouched colony on an island off of Mexico.

Early colonists deforested many parts of the country. Lumberjacks in California felled 95% of old growth redwoods, to build up San Francisco and other western cities:

Photos by A.W. Ericson, Library Special Collections in the Humboldt State University.

People today have inherited a planet that’s been greatly diminished by our ancestors.

In the late 1800's, something remarkable started to happen. Some people started caring about the environment and about wildlife. Some things began to improve. The National Parks system started with Yellowstone in 1872, then Sequoia and Yosemite in 1890. Some giant Sequoia and Redwood groves were protected around the turn of the century. A treaty banned sea otter hunting in 1911. At the time, only 1,000 otters remained in the wild, but numbers slowly rebounded until they eventually filled much of their original range. Whaling continued for decades longer until it was mostly banned in 1982. Clear-cut redwood forests started to grow back. California condors nearly went extinct in the wild, but were raised in captivity and reintroduced.

This isn’t a world-wide success story, though. A few parts of the developed world have made environmental progress. The first world is starting to grow forests faster than it loses them, but the third world is still in the process of deforestation. We are rapidly losing some of the most diverse tropical rainforests in the world in Madagascar, Borneo, and the Amazon.