There are a lot of human beings on this planet. Present headcount? Approximately 7.4 billion homo sapiens, trending toward more than 11 billion by 2100. That’s a lot of mouths to feed.

It wasn’t always this way. For most of our history, our species has been a relatively small band of probably less than one million people. In this video from the American Museum of Natural History, we watch as humans expand their presence around the globe over tens of thousands of years. Migrating from our birth place in Africa around 200,000 years ago, it takes us until 50,000 B.C. to reach the Bering land bridge and traverse the Malayan archipelago to touch Australia. It’s 30,000 B.C. before we reach down the west coasts of north and central America. All the while our population, shown graphed against time at the bottom of the screen, remains nearly flat.

All that changes around 10,000 B.C., at the advent of farming. After the first of two major population bursts, there are 170 million people by 1 A.D. The map shifts to a flat projection, and yellow dots, each representing 1 million people, begin popping up as civilizations—the Roman Empire, the Han Dynasty—rise and fall. It’s fascinating to watch the steady population growth, hindered only slightly by the Black Death in the 14th century, reaching a billion people for the first time around 1800.

Not long after, we really get cooking. The industrial revolution and advances in medicine lead to a exponential “hockey stick” of population growth not even the world wars can dent: As the video notes, it took our species 200,000 years to reach 1 billion people, and only 200 years to reach 7 billion.

Current projections estimate our population will top out at 11 billion in 2100, but we could exceed that number if the projections turn out to be wrong.

This makes contemporary efforts at conservation, family planning, and pollution control even more important. The Global Footprint Network estimates that our global civilization currently uses 1.6 times the resources our planet generates—that it takes 18 months, in other words, to regenerate the resources we use in one year’s time. Add another 4 billion people to the mix, and we’re likely to be looking at a whole other planet.