600,000 years ago: Tracing the origins of Arabica coffee back to Ethiopia

Scientists in Madrid have sequenced the highest-quality reference genome of Arabica coffee, the most popular variety of coffee. This genome reveals secrets about its lineage, which dates back thousands of years and spans multiple continents. The study, published in Nature Genetics, shows that Arabica coffee was developed over 600,000 years ago in the forests of Ethiopia through natural crossing between two other coffee species.

The population of Arabica coffee has fluctuated over thousands of years, influenced by periods of Earth’s warming and cooling. It was eventually cultivated in Ethiopia and Yemen before spreading around the world. This crop is essential for major coffee chains like Starbucks and Tim Hortons. However, due to low genetic diversity and susceptibility to pests and diseases, Arabica coffee can only be grown in specific regions with favorable conditions.

Understanding the origins and breeding history of Arabica coffee is crucial for developing new cultivars that are better adapted to climate change. The study used cutting-edge DNA sequencing technology to sequence 39 varieties of Arabica, including an 18th-century specimen named by Swedish naturalist Carl Linnaeus. The researchers created the most advanced Arabica reference genome to date, which is now available in a public database.

Arabica coffee, which makes up 60% of the world’s coffee products, helped people start their day for centuries. Scientists have determined that Arabica coffee was formed as a natural hybridization between Coffea canephora and Coffea eugenioides, indicating that this event predates modern humans and coffee cultivation. The geographic divide of wild and cultivated Arabica varieties suggests that coffee cultivation may have originated in Yemen around the 15th century.

The diversity of Yemeni coffee varieties may be the foundation of all modern Arabica varieties. Coffee cultivation has not involved extensive crossbreeding, unlike other crops like corn or wheat. Modern coffee varieties likely date back to ancient times, chosen for their taste and grown for generations. This research sheds light on the long history and evolutionary path of Arabica coffee, a beloved beverage enjoyed around the world.