Ancient Maize in Brazil Challenges Domestication Origins Theory

Brazilian researchers have uncovered evidence that partially domesticated maize samples from Peruaçu Valley may point to South America as a secondary center for maize domestication. The findings could reshape understanding of this vital crop’s ancient history and global significance.

A Revolutionary Discovery in Peruaçu Valley

In the heart of Brazil’s Peruaçu Valley, archaeologists and scientists have unearthed maize samples that challenge the long-held belief that maize domestication was solely completed in Mexico. These semi-domesticated maize remnants, including cobs, grains, and straw, were analyzed and dated 1,010–500 years ago, predating European colonization of South America.

The study, published in Science Advances by a team from the University of São Paulo (USP) and EMBRAPA (Brazilian Agricultural Research Corporation), revisited samples initially excavated in 1994. These specimens, found in caves adorned with ancient rock paintings, represent the furthest documented spread of maize with primitive traits from its Mexican origin, some 7,150 km away.

“This research highlights the critical role of past Indigenous communities in shaping South America’s maize varieties through careful selection and management of traits,” said Fábio de Oliveira Freitas, an EMBRAPA researcher and a co-author of the study.

The Path of Maize Across the Americas

Maize, or corn (Zea mays), originated 9,000 years ago in Mexico, evolving from a wild grass called teosinte. Over millennia, it spread across the Americas, adapting to diverse environments and undergoing further domestication.

In Peruaçu Valley, the semi-domesticated samples exhibited characteristics bridging the gap between wild teosinte and fully domesticated maize. One key indicator was the number of grain rows per cob. While modern maize can have up to 26 rows, the Peruaçu samples showed only four to six rows, resembling their ancestral form.

“These traits confirm that the domestication process was incomplete but advanced,” said Flaviane Malaquias Costa, the study’s lead author and a researcher at USP. “Our findings suggest that Indigenous communities in South America played a significant role in finalizing maize domestication, selecting traits that adapted well to local conditions.”

The samples were also genetically linked to the Entrelaçado race, a maize variety found in Brazil’s Rondônia and Acre states and even Uruguay. This link supports the idea that people in South America helped to change the genes of maize, which came from Mexico about 6,000 years ago. South American populations played a role in this genetic diversification, indicating a complex and interconnected history of maize domestication in the region.

Cultural and Archaeological Significance

Peruaçu Valley’s caves offer a rare glimpse into the lives of ancient Indigenous populations. Rock paintings showing maize and other crops reveal that the people there understood agriculture’s importance. They probably knew it well. Maize discovered in baskets hidden in caves might have been gifts to those who passed away. This fact stresses its cultural and spiritual value.

Archaeological evidence shows that humans settled in the valley from 10,000 to 9,000 years ago. Maize appeared in this region around 1,500 years ago, highlighting the farming skills of these people. They learned to grow maize with great cleverness.

“This is not just about plant domestication; it’s about understanding the relationship between people and their environment,” said Elizabeth Ann Veasey, a co-author and professor at USP. “Indigenous peoples were not merely passive users of maize; they actively shaped its evolution, and their descendants continue to do so today.”

Implications for Global Agriculture and Geopolitics

The discovery of partially domesticated maize in Peruaçu Valley has significant implications for global agriculture and geopolitics. If researchers confirm South America as another center for maize domestication, Brazil could earn recognition as a necessary protector of maize’s genetic history, thereby affecting farming and global rules.

Freitas explained, “This would change maize’s status under global agreements.” Maize would shift from an exotic crop to one requiring protection in its native regions, which could impact property rights and conservation strategies. The urgent need to protect and preserve maize’s genetic diversity is crucial and should be a priority for all involved in agriculture and conservation.

The study highlights the value of old farming methods. Indigenous groups continue to cultivate and develop maize. They preserve varieties with untapped potential for agriculture today. Traditional maize varieties hold great possibilities for modern farming.

Costa stated, “We’re connecting the past and the present.” Researchers link ancient remains to today’s maize varieties. The research team is now working with international partners to conduct archaeogenetic analyses, aiming to sequence the entire genome of the Peruaçu maize samples and precisely map their evolutionary tree. This ongoing research will provide further insights into the history and evolution of maize, and its implications for modern agriculture and conservation.

Rewriting Maize’s History

Discoveries in Peruaçu Valley question the usual story of how maize was domesticated. These findings highlight the crucial role of South America’s Indigenous peoples in developing this vital crop.

Researchers studying maize discover more than just genetic clues. They reveal tales of human creativity and persistence. This research shows how farming, culture, and science connect. It shapes our understanding of food in the past and future.

Archaeologists, geneticists, and Indigenous communities collaborate. Their efforts show maize’s lasting importance in ancient and modern times. The legacy of maize is still growing and changing.

Also read: Brazilian Scientists Discover Gene Offering Resistance to COVID-19 Infection

Semi-domesticated maize in Brazil’s Peruaçu Valley reveals a new perspective on the crop’s history. Science studies this complex history. It demonstrates the profound effect of Indigenous knowledge. This influence links various places and eras through an important agricultural legacy. This connection is significant.