Thousands of years ago, ancient Egyptians looked up at the night sky and saw their moon god Thoth in two very different creatures: a white bird with a curved beak and a silver-furred monkey. For decades, scholars wondered how these two completely different animals came to represent the same god. Now, a study has found a surprisingly simple answer: both animals shimmer like the moon itself.
The researchers, Nathaniel Dominy at Dartmouth College and Catherine Hobaiter at the University of St Andrews, wanted to understand why the sacred ibis and the sacred baboon were both sacred to Thoth. "Why would two strikingly disparate animals be used to represent a deity known for wisdom?" they asked. To find out, they turned to science.
Using a tool called a spectrometer, which measures exactly how much light bounces off a surface, the team tested 12 animals at the American Museum of Natural History in New York. They aimed the device at the fur of the sacred baboon (Papio hamadryas) and the white feathers of the sacred ibis (Threskiornis aethiopicus), and both reflected light almost exactly matching moonlight. Meanwhile, other closely related animals like the olive baboon reflected a greenish color instead, showing that the connection wasn't random.
The ancient Egyptians had other choices too. At least three different ibis species lived in Egypt, but only the white one was chosen. Among baboons, only the silver-coated Hamadryas monkey shimmered like their moon god. "Sacred ibises and hamadryas baboons are different in many ways, but one thing that unites them is their moon-like color," the researchers said.
Salima Ikram, an Egyptologist at the American University in Cairo who was not involved in the study, called the findings "one of the first feasible explanations" for why the Hamadryas baboon became one of Thoth's totemic animals. She said the research helps explain something Egyptologists have long puzzled over.
What makes this discovery especially striking is how rare Egyptian reverence for baboons really was. In most African cultures, baboons have a negative reputation because they steal crops. But ancient Egyptians may be the only civilization ever to not just respect baboons, but actually worship them as gods. Dominy and Hobaiter noted that this stands out as remarkable in human history.
The study, published in the journal Time and Mind, offers more than just an answer to an ancient puzzle. It provides a rare window into how ancient Egyptians thought. "Opportunities to understand their minds are rare," the researchers said. In this case, looking at the moon helped scholars understand how people thousands of years ago connected the sky to the animals they saw around them.