The cup of coffee you drank this morning might trace its roots back 600,000 years.
A new study published in Nature Genetics on April 15, 2024, has revealed that Coffea arabica—the world’s most popular coffee species—emerged through natural crossbreeding between two other species long before human cultivation.
Researchers from the University at Buffalo and Nestlé examined genetic data from coffee plants around the world to construct a comprehensive family tree of Coffea arabica. Their findings indicate that the species originated approximately 600,000 years ago, when Coffea canephora (robusta) and Coffea eugenioides hybridized naturally in the wild.
“In other words, this occurred long before any human intervention,” said Victor Albert, a biologist at the University at Buffalo and co-lead author of the study.
The wild ancestors of arabica first appeared in the highlands of Ethiopia, but it was in Yemen, during the 1400s, that the beans were first roasted and brewed—marking the beginning of coffee culture as we know it today.
By the 1600s, legend has it that Indian monk Baba Budan smuggled seven coffee beans from Yemen to India, laying the foundation for global coffee cultivation.
Today, arabica accounts for 60–70% of the world’s coffee production, prized for its smooth, mildly sweet flavor. It forms the backbone of beverages served by leading brands such as Starbucks, Tim Hortons, and Dunkin’.
The remaining 30–40% of the market comes from Coffea canephora—commonly known as robusta—a stronger and more bitter relative of arabica.
To uncover arabica’s genetic history, the team analyzed the genomes of C. canephora, C. eugenioides, and more than 30 arabica samples, including an 18th-century specimen preserved in the Natural History Museum in London. This very sample was once studied by Swedish botanist Carl Linnaeus when he officially classified the species.
The study shows that arabica’s population has fluctuated greatly over millennia—thriving during warm and wet periods, but shrinking during dry epochs. These “population bottlenecks” left arabica with low genetic diversity, making it highly vulnerable to diseases such as coffee leaf rust, which costs the global coffee industry billions each year.
Researchers also examined a rust-resistant arabica variety to identify genetic markers that could help breeders develop hardier plants. These insights, scientists say, could be key to safeguarding the species against the growing threats of pests and climate change.
“This study not only clarifies arabica’s evolutionary history but also provides crucial clues for protecting one of the world’s most valuable crops,” said Fabian Echeverria, adviser at the Center for Coffee Research and Education at Texas A&M University, who was not involved in the research.
By retracing arabica’s ancient lineage, scientists hope to ensure a sustainable future for coffee cultivation—keeping plants healthy, farmers resilient, and morning cups full for generations to come.
