Aboriginal people harvested this native grass for millennia. Scientists have now found an odd trait in its DNA

Aboriginal people have long harvested a native grass known as channel millet, scientifically named Echinochloa turneriana, for thousands of years. Now, scientists have uncovered a unique genetic characteristic in the plant that suggests a possible link to human influence. The findings, published in the journal Nature Communications, highlight the intricate relationship between Indigenous Australians and their environment, revealing how traditional practices might have shaped the evolution of native flora. Located in the remote Channel Country of southwest Queensland, the Mithaka people have lived in the region for at least 3,000 years. Their ancestors were integral to the development of a transcontinental trade and exchange system, with plants playing a central role in their daily lives. Over 200 different species were used for food, medicine, materials, and ceremonies. Among these, channel millet stood out as a vital resource, particularly during periods of seasonal flooding when the grass thrived. The new study focuses on the genetic makeup of channel millet, revealing that it possesses a high degree of chromosomal complexity. Unlike most organisms, which typically have two copies of each chromosome, one inherited from each parent, this grass has 12 copies of each chromosome. This condition, known as polyploidy, occurs when an organism acquires multiple sets of chromosomes, either through accidental reproductive events or hybridization. Polyploidy is commonly observed in domesticated crops such as wheat, rice, and sugarcane, where it often results from human intervention. However, the researchers caution that the presence of polyploidy alone does not confirm domestication. Natural occurrences of this phenomenon have existed for millions of years, driven by evolutionary processes rather than direct human action. That said, the study notes that human activity has significantly accelerated and influenced such genetic changes, sometimes unintentionally. Archaeological evidence further supports the deep connection between the Mithaka people and channel millet. Previous research has identified numerous grinding stone quarries across the region, used to process the seeds of native grasses, herbs, shrubs, and trees. These sites indicate a sophisticated understanding of local ecosystems and food resources. Together, they form an interconnected cultural landscape of exceptional significance, recently recognized and added to the National Heritage List. One notable artifact from the area is an Aboriginal hearth, which burns plant seeds, making them resistant to erosion. Archaeobotanists analyzing these hearths have gained valuable insights into ancient Mithaka food production systems. The hearths serve as physical records of how Indigenous peoples managed their environment, using fire to enhance food preparation and storage. The study's lead researcher, Michael Westaway, emphasizes the broader implications of the findings. He explains that while the genetic complexity of channel millet does not definitively prove domestication, it underscores the potential for human interaction to shape plant evolution. This aligns with growing interest in understanding how Indigenous peoples have historically influenced vegetation communities in Australia, a field that is gaining traction within Australian archaeology. Further research is needed to determine whether human activities directly contributed to the polyploid nature of channel millet. Such investigations could provide deeper insight into the ways in which traditional ecological knowledge has shaped the biodiversity of the region. For now, the discovery offers a compelling glimpse into the enduring relationship between the Mithaka people and the native plants they have relied upon for generations.