Unraveling the Sweet Evolution of Chocolate's Past

In a groundbreaking discovery, new research published in Communication Biology challenges the long-held belief that Mesoamerica was the birthplace of chocolate. The study, led by Omar Cornejo, a population geneticist at Washington State University, suggests that the domestication of cacao actually began in the region of present-day Ecuador and the upper Amazon basin around 3,600 years ago.

The research team analyzed the genomes of 200 cacao plants to trace the origins of domesticated cacao. Their findings reveal that Criollo, an extremely rare variety of chocolate, was the first to be domesticated, contrary to previous assumptions that it originated in Central America.

Criollo is cherished by candy fans for its deep and complex flavour, but its susceptibility to disease has made it a rarity, accounting for just 5% of the world's chocolate crop. Interestingly, Criollo trees found in Central America are markedly different from those found in the Amazon basin.

The earliest evidence of cacao usage in the Americas was found in Mayo-Chinchipe sites in Ecuador, which are about 5,300 years old. Archaeologists have traditionally assumed that Mesoamericans were the first to cultivate cacao, but the new study provides a new origin story for chocolate, suggesting that it was first used in Ecuador before spreading to Mesoamerica.

The ancient relative of Criollo, called Curaray, is believed to be the source of its domestication. The domestication of Criollo may have occurred between approximately 2,400 and 11,000 years ago, with the most likely scenario being around 3,600 years ago.

Michael Blake, co-author of the study, suggests that cacao "caught on" and spread northwards through farming. It was traded from the Mayo-Chinchipe to groups along the Pacific coast and then north to Mesoamerica. Cacao spread northwards by farmers in what is now Colombia, Panama, and other parts of Central America and southern Mexico.

The genetic differentiation in a domesticated plant is a telltale sign of domestication, and Criollo is the only cocoa population with high genetic differentiation, further supporting the theory that it was the first variety to be domesticated. This new understanding of chocolate's origins sheds light on its rich history and the role it played in the cultural development of the Americas.