The evolution of foraging

Today, most people buy the food they need from markets, grocery stores, and restaurants. Imagine if you suddenly had to go out into the wilderness to find all the food you needed. Could you do it?

That’s what our species (Homo sapiens) has done for almost all our time on Earth. The first Homo sapiens appeared about 250,000 years ago. Until some people started to farm about 12,000 years ago, all humans were foragers. Foraging means relying on food collected from nature. And before Homo sapiens evolved, other species of humans—like Homo erectus and Homo neanderthalensis—had already been foraging for millions of years. Humans, like many other animals, are natural foragers.

Foragers gather plants, small animals, and insects. They scavenge animals killed by other predators, and they hunt larger animals. Foraging is often called hunting and gathering.

Humans aren’t the only foragers. Lots of animals do it. But our collective learning skills helped us get very good at it. As our language skills got more complex over time, humans were able to pass more detailed information to their children. With each generation, people got better at foraging. They came to understand which plants were safe to eat, how to make better stone tools, and even developed strategies for hunting the best animals.

You could say that foraging made us human—it drove the evolution of the different human species. Around 4 million years ago, the number of fruit trees in African rain forests declined as the climate got cooler and drier. As a result, many of our hominin (bipedal primates) ancestors had to get better at finding food from other food sources. As they gradually needed to find and remember new food sources and they consumed more meat, they developed new traits. Gradually, early species of hominins began walking on two feet, lost most of their body hair, developed smaller intestines and larger brains, and became better communicators and toolmakers. Eventually, our own species evolved.

Humans gradually developed hunting skills. At first, they probably scavenged meat that had been killed by other animals. They used stone tools, like hand axes, to butcher the animal and crack its bones for marrow. As they developed better weapons and strategies, they also learned to work together in larger numbers, allowing humans to hunt larger animals.  

One of the most significant steps that humans ever took was learning to control fire. They probably learned this skill by tending wildfires started by lightning. No one knows exactly when it happened, but scientists believe some groups of Homo erectus began using fire to cook over a million years ago. Cooked food was easier to digest and provided more nutrition, which contributed to even larger brains and brain development. Eating together around a fire may have also promoted language development and collective learning.

The economics of foraging

Each foraging society was different depending on the environment they lived in.. However, we can make some generalizations about the things foraging societies shared in common:

• They moved around and foraged in a territory.
• They had detailed knowledge of their environments and where animals and plants were at what times of the year.
• If they lived in a harsh environment that provided fewer resources, they foraged in a very large area. Where food was plentiful, a smaller territory was enough.

Most foragers moved frequently. They slept in temporary camps. They might move with the seasons to follow animal migrations or the ripening of different plant food sources. Foragers usually lived in small groups of 15 to 30. When food became scarce, or conflicts arose, they split up. Forager populations grew slowly, if at all. Mother’s milk provided the only food for infants. In these close-knit groups, foragers usually shared the food they collected. Some scholars claim that foraging societies were more peaceful and more equal than the farming societies that came later. For millions of years, this was how all humans—our species and others—lived.

Debates about foraging

Foragers—both ancient and modern—are the focus of lots of study by archaeologists and anthropologists. There are many debates between different scholars who interpret the evidence from foraging societies differently.

For example, until recently, scholars thought that men did the hunting in foraging societies, while women did the gathering. However, recent studies have challenged this view. Among foraging societies that exist today, men and women are flexible about who hunts, and, in some cultures, the hunting and gathering roles change. Today, most scholars believe that foraging societies of the past had flexible gender roles, depending on individual skills, knowledge, and the local environment.

Another ongoing debate among experts is about the quality of life that foragers enjoyed. Traditionally, foragers were viewed as barely surviving and having short, miserable lives. In the 1960s, however, anthropologists studying modern foragers revealed that foragers enjoy good nutrition from food collected in just a few hours a day. The rest of their day is spent socializing. Yet, in the 1980s, this view was challenged. No agreement has yet been reached.

A third debate concerns how much human foragers changed their environments. For a long time, it was assumed that humans had little effect on nature until they developed agriculture. But since the 1960s, scientists have found two types of evidence that foragers had a big impact on their environment. The first evidence is of large fires set by foragers. Foragers set fire to large areas of land to drive out animals for hunting. Burning land also promoted the growth of fresh plants that provided food and attracted animals. The Indigenous Australian use of this practice was given the name firestick farming. These fires turned scrubland into grassland and suppressed some species, which transformed whole ecosystems.

The second piece of evidence involves megafauna. Whenever humans migrated to new parts of the world, many species of megafauna went extinct. In North and South America, about 75% of the animals weighing more than 100 pounds went extinct within a couple of thousand years after humans arrived. These animals included mastodons, camels, horses, and saber-toothed tigers. In Australia, where humans are thought to have arrived about 40,000 to 60,000 years ago, similar extinctions occurred roughly 30,000 years ago. The rate of extinction was about 85% and included giant kangaroos and marsupial lions.

In Eurasia, the extinctions occurred more gradually and included mammoths, woolly rhinoceroses, and giant elk. The debate about the exact causes of extinction continues. Some claim that these animals could not adapt or evolve fast enough to survive alongside the newly arrived humans. Today, Africa is the continent with the most species of megafauna. Scholars believe that’s because Africa’s megafauna evolved alongside humans, adapting to human hunting tactics. Perhaps a combination of changing climate, human hunting, and other changes brought about by humans caused the mass extinctions seen on other continents.