Avocados: A Love Story Spanning Millennia, Not Just a Millennial Trend
Avocados, the creamy green fruit that has become synonymous with millennial brunch culture and avocado toast, have a history far deeper and richer than the last decade’s dietary fads. While trendy cafes might make it seem like avocados are a modern obsession, groundbreaking research has revealed a love affair between humans and avocados stretching back over 11,000 years, rewriting our understanding of early agriculture and human dietary habits in the Americas.
A recent study, meticulously analyzing artifacts from a rock shelter in Honduras, provides compelling evidence that humans were not only consuming avocados but actively cultivating them as early as 7,500 years ago. This discovery challenges the prevailing narrative of agricultural development in the Americas, suggesting that tree domestication predates the widespread cultivation of staple crops like corn.
"This is really the best evidence we have for human-directed avocado evolution. It fills a big hole in our knowledge," stated Dolores Piperno, a senior scientist emerita and archaeobotany curator at the Smithsonian National Museum. The findings, published in the Proceedings of the National Academy of Science, offer a fascinating glimpse into the ancient relationship between humans and avocados, shedding light on the early stages of agriculture and the profound impact humans have had on shaping the fruits we enjoy today.
The study centers on the El Gigante rock shelter in western Honduras, an extraordinary archaeological site boasting an unparalleled collection of plant remains spanning the last 11,000 years. The shelter, over 120 feet wide and 55 feet deep, served as a dwelling for generations of people, leaving behind layers of discarded materials, including the remnants of over 20,000 plants like avocados, bottle gourds, agave, beans, and squashes.
The key to the study’s significance lies in the remarkable longevity of human habitation at El Gigante and the sheer abundance of ancient kitchen waste preserved within its confines. "These kinds of finds in archeology are incredibly rare and provide a window into the evolutionary history of plant domestication," explained Douglas Kennett, a professor of environmental archeology at the University of California, Santa Barbara, and the paper’s senior author.
Scientists began excavating the El Gigante site in 1995, but it wasn’t until 2018 that they commenced the painstaking process of radiocarbon dating and analyzing the vast collection of plant remains. Seven years later, their meticulous work has culminated in groundbreaking findings that reshape our understanding of avocado domestication.
The research team meticulously examined 1,725 avocado fossils, including rinds and pits, revealing significant changes in the fruit’s shape and size over time. The fossils showed a clear trend towards thicker rinds, larger pits, and a greater proportion of edible flesh, all indicative of human selection and cultivation.
While avocado fossils have been discovered in other locations, the El Gigante site is unique in providing definitive evidence of avocado domestication. "It’s really the first evidence of a sequence that shows the initial exploitation, management and then human-selection of the trees leading to domestication," noted Piperno.
It is possible that avocado farming began elsewhere earlier, but this is the only well-dated site showing a clear progression of domestication. The study underscores the importance of long-term archaeological sites in tracing the evolutionary history of plants and understanding the complex interplay between humans and their environment.
Beyond its implications for avocado history, the study also challenges the traditional narrative of agricultural development in the Americas. Amber VanDerwarker, an expert in ancient plants and agriculture at the University of California, Santa Barbara, and the lead author of the study, highlights the shift in perspective. "The narrative in the Americas has often been that everyone was hunter-gatherers until corn appeared and then they became farmers."
However, recent findings by ethno-botanists and archeologists suggest that agriculture in the Americas began with trees, preparing the way for the later cultivation of field crops like corn. "These people literally domesticated their forests," said VanDerwarker, emphasizing the importance of tree management in shaping early agricultural practices.
When corn eventually arrived, the people of Central and South America "already understood the whole notion of planting seeds and managing growth," she added. This suggests that the skills and knowledge gained through tree domestication facilitated the adoption of other agricultural practices.
The story of the avocado’s journey from wild fruit to grocery store staple is intertwined with the history of megafauna, the giant animals that roamed the Americas until about 12,500 years ago. These included mammoths, mastodons, and giant sloths, creatures capable of swallowing avocados whole and dispersing their seeds across vast distances.
"Think about mammoths and mastodons. They were the only animals that could eat the fruit whole and pass the seed," said VanDerwarker. Wild avocados originated in central Mexico, and these massive animals played a crucial role in spreading them throughout Central and South America long before the arrival of humans.
The extinction of megafauna around 12,500 years ago, possibly due to climate change and overhunting by humans, created an ecological void that humans eventually filled. "These plants were primed for this mutualistic kind of interaction, so humans stepped in," said Kennett.
As humans began inhabiting the El Gigante rock shelter, they initially relied on hunting and gathering for sustenance. Over time, they started to cultivate the fruit-bearing trees in their surroundings, including avocados, palms, and soursops.
The avocados consumed by these early inhabitants were of the guatemalensis variety, characterized by a round shape and thick, warty skin. The Hass avocado, the most popular variety in the United States today, is a hybrid of Mexican and Guatemalan avocado types.
The scientists observed a clear progression from exploitation to management and finally to domestication of avocado trees. "Within a couple of thousand years they were clearly managing their avocado trees," said VanDerwarker. Evidence suggests that they were selectively pruning branches and thinning the fruits to promote larger yields.
Around 4,500 years ago, the fossil record reveals significant increases in fruit size and rind thickness, marking a crucial turning point in avocado domestication. "This is the earliest documentation of avocado domestication," said Kennett.
The early farmers also appeared to be selecting for thicker rinds, which protect the fruit and make it easier to scoop out the flesh. Thicker rinds are particularly important because avocados only ripen after being picked from the tree, allowing for easier storage during maturation.
Although avocados were independently domesticated at least three times in the Americas, the findings at El Gigante offer the oldest documented example. These early avocado consumers likely enjoyed the fruit in much the same way we do today, splitting it open and scooping out the flesh.
Guacamole, it turns out, may not be a modern invention. "Chili peppers go back to about the same time period," said Kennett. While chips may not have been available yet, the possibility of early guacamole is certainly intriguing.
Maize, or corn, wasn’t domesticated until at least 9,000 years ago and didn’t reach the El Gigante area until around 6,000 years ago. The first corn found in the El Gigante rock shelter dates back approximately 4,200 years.
While the people living at El Gigante might have been surprised by the size and fleshiness of modern avocados, they likely wouldn’t be surprised by our current infatuation with the fruit. In fact, they might have wondered what took us so long.
Back in the 1980s, avocados were a rarity in U.S. supermarkets. It wasn’t until the 1990s, when the California Avocado Commission launched a public relations campaign to educate consumers about how to eat avocados and determine when they were ripe, that sales began to soar.
Since 2000, U.S. per capita consumption of avocados has increased dramatically, from just under two pounds to almost nine pounds per person. Today, the avocado industry is dominated by the Hass variety, with its black, pebbly rind. All Hass avocado trees are clones of the original Hass tree, developed by Rudolph Hass, a postman in Los Angeles.
While avocados are grown in California and Florida, the vast majority consumed in the United States today come from Mexico, accounting for over 90% of the supply. Avocados have become the highest-value agricultural commodity imported into the United States, surpassing bananas in 2017.
"The increase in consumption is unbelievable, it’s amazing how it’s been assimilated," said Luis Ribera, an agricultural economist with Texas A&M University. "They’ve become a grocery store staple."
The avocado’s journey from ancient wild fruit to millennial food trend is a testament to its enduring appeal and the power of human ingenuity. The research at El Gigante provides a fascinating glimpse into the origins of avocado domestication and challenges our assumptions about the development of agriculture in the Americas. The next time you enjoy a slice of avocado toast, remember that you are participating in a culinary tradition that spans over 11,000 years, connecting you to the ancient peoples who first cultivated this luscious green fruit.
