Africa’s first Iron Age culture had a sweet tooth

 Africa’s first Iron Age culture had a sweet tooth
Africa’s first Iron Age culture had a sweet tooth

Chemical traces of 3,500-year-old beeswax on central Nigerian potsherds shed light on an often invisible aspect of ancient diets—and a bit about what fueled the culture that launched Africa’s Iron Age.

These farmers were super into metal

Terms like “Iron Age” only have meaning if you’re talking about a particular place, since periods of technological innovation didn’t begin at the same moment everywhere in the world. People in several regions discovered, at different times, how to turn iron ore into workable metal. Some cultures worked it out on their own, while others learned the new technology from neighbors, trading partners, or conquerors.

In sub-Saharan Africa, the Iron Age began sometime between 1000 and 550 BCE, and it began with the Nok people, a culture that sculpted elaborate terracotta figurines, farmed millet, and developed iron smelting. The first traces of Nok culture appear in Nigeria’s archaeological record around 1500 BCE, and they don’t vanish until 2,000 years later, around 500 CE. Archaeologists still aren’t sure whether the Nok culture arose in Nigeria or whether the Nok people moved south from someplace like modern Mauritania, Mali, Niger, or Chad, where millet is an indigenous crop.

That’s a familiar debate in archaeology: Did the technology of millet farming spread south from one group of people to another, or did a group of millet farmers move south and bring their crops with them? In the case of the Nok, archaeologists like Peter Breunig lean toward the idea that farmers actually migrated south into what is now central Nigeria. There, they farmed millet and coexisted with other groups of people who mostly made their living by hunting, gathering, and fishing. But the Nok couldn’t have lived on millet alone, and Breunig and his colleagues are still trying to learn whether they also raised livestock or hunted—or did a bit of both. What kind of meat fueled the rise of Africa’s Iron Age?

Spoiler alert: We still don’t know. But thanks to a recent study, in which a team led by Julie Dunne of the University of Bristol looked for microscopic chemical residues on 458 Nok potsherds, we do know that the Nok apparently ate honey.

A few of the Nok culture's trademark terracotta figurines. Most figurines depict people or animals, and the human ones are known for their elaborate hairstyles.
Enlarge / A few of the Nok culture’s trademark terracotta figurines. Most figurines depict people or animals, and the human ones are known for their elaborate hairstyles.

That’s an interesting discovery for a handful of reasons. First, it tells us something new about the Nok, a fascinating culture we understand mostly from their terracotta sculptures. Second, it flips the usual way of things in archaeology completely on its head. At most archaeological sites, the only traces of ancient meals are usually animal bones and perhaps a few seeds or plant fragments. Foods other than meat and plants are totally invisible in the archaeological record.

“Plant and animal remains from archaeological sites usually reveal only a small part of what prehistoric people had been eating,” said Goethe University archaeologist Katharina Neumann, a co-author of the study. For the Nok, archaeologists now have a piece of the puzzle that’s usually missing—but still don’t know what kind of meat they ate.

What’s all the buzz about?

The soil in central Nigeria is so acidic that bones just dissolve in it, so archaeologists have no butchered pieces of game or livestock from ancient Nok larders. To find out what was on the menu for Nok people when they weren’t busy farming and inventing ironworking, Dunne and her colleagues examined the insides of broken ceramic pots from a dozen Nok sites, looking for chemical traces of past meals.

They used a technique called gas chromatography/mass spectrometry, which examines the chemical makeup of a substance by heating it. The heat separates the substance into the individual compounds that make it up, and a mass spectrometer then identifies each chemical based on its mass.

Specifically, the team was looking for lipids, molecules that make up things like fats, oils, and waxes. Different species and materials contain different types of lipids. Previous studies have used lipid residues to identify traces of ancient dairy products or tell whether people ate cattle or goats and sheep.

Dunne and her colleagues expected to find the same kind of information: lipids that would reveal whether people had eaten domesticated cattle or wild deer, for example. Instead, they found lipids that matched the ones in samples of modern beeswax. Out of 458 potsherd, 66 contained enough lipid residue to work with, and 25 of those contained lipids that matched those found in modern beeswax samples.

“We originally started the study of chemical residues in pottery sherds because of the lack of animal bones at Nok sites, hoping to find evidence for meat processing in the pots,” said Goethe University archaeologist Peter Breuing. “That the Nok people exploited honey 3,500 years ago was completely unexpected and is unique in West African prehistory.”

Combing the past for answers

To be clear, what’s surprising is that archaeologists found the lipid residue, not that Iron Age people were using honey. Rock art in Namibia’s Didimia Gorge and elsewhere in southern Africa, dating back to 40,000 years ago, depicts bees, honeycombs, and honey collecting. And a lump of mixed beeswax and resin, used to haft a bone point, turned up in a 40,000 year old layer at Border Cave in South Africa.

Modern hunter-gatherers—and even rural farmers in several parts of the world, including West Africa—still collect honeycomb as a food source. Honey is sweet, of course, but it’s also packed with protein and energy, especially if you eat the comb with the larvae and pupae still inside, as the Efé people of the Ituri Forest often do.

Honey also ferments into alcohol and makes a decent medicine for certain minor ailments and wounds. Beeswax, the stuff honeycomb is made of, is perfect for sealing containers or providing fuel for candles or lamps. If you’re willing to climb a tree and deal with the bees, beehives offer a very useful resource, and it’s not surprising that ancient people figured that out and got in on the action. What’s surprising is that 3,500 years later, microscopic traces of that sticky, sweet staple were still clinging to the insides of long-discarded dishes.

The lipid residues had been absorbed into the inner surface of the containers, which suggests that they’d been heated slowly, stored for a long time, or perhaps both. That means people might have melted the honeycomb to separate the beeswax from the honey and brood (larvae and pupae—pro tip: if you want to annoy a beekeeper, insist on referring to brood as “baby bees”). An ancient cook may also have included the honeycomb in a dish for flavor.

One pot in Dunne and her colleagues’ study contained lipids from both beeswax and meat. Today, the Okiek people of Kenya use honey to preserve their smoked meat, which can last for up to 3 years. The ancient Nok may have done doing something similar. It’s also remotely possible that the Nok were beekeepers. Modern beekeepers in parts of Nigeria still practice a traditional approach, using clay beehives on the ground or in trees. However, the pots in the study seem too small to have been used for that purpose.

“Chemical residues of beeswax in potsherds opens up completely new perspectives for the history of resource exploitation and ancient diet,” said Neumann. That’s likely to mean more investigation of sherds from other Nok sites—and other cultures from sub-Saharan Africa—to try to learn more about how people used resources from bees.

Nature Communications, 2021 DOI: 10.1038/s41467-021-22425-4  (About DOIs).