There is a long-held belief that agriculture changed everything for human beings. Agriculture meant a stable food supply, surpluses, an ability to thrive despite natural environmental changes.

But a new study, published in December in the Proceedings of the National Academy of Sciences of the United States, challenges the idea that the start of agriculture 10,000 to 12,000 years ago is responsible for boosting the human population growth rate. Radiocarbon dating analysis shows that prehistoric hunter-gatherer human populations in what is now Wyoming and Colorado grew at the same rate as farming societies in Europe.

“It’s pretty mind blowing,” said Erick Robinson, a University of Wyoming post-doctoral researcher on the project.

Bob Kelly, professor of anthropology at the University of Wyoming, was looking at the relationship between prehistoric population sizes and climate change, using radiocarbon dating on charcoal found in prehistoric hearth sites. Scientists can use this data to estimate population growth rates for a given period of time. Previously, scientists studied population data over short time spans, like 500 years. Looking at population data is not new. What is new is the UW research team looked at growth rate across a large span of time instead of just 500 years.