Why are the origins of corn difficult for archaeologists to fully explain?

The origins of corn are difficult for archaeologists to fully explain due to several factors related to the archaeological record and the plant's evolutionary history:

• Limited Archaeological Evidence: Understanding Mesoamerican agricultural origins is hampered by the fact that few relevant archaeological sites have been explored. Furthermore, early corn may have been primarily exploited for the sugar content in its stalks and leaves rather than its kernels; because kernels were less important in these early contexts, they were less likely to be preserved, contributing to their rarity in the early archaeological record.1
• Evolutionary Complexity: While teosinte is considered the wild ancestor of corn, no wild grass possesses the robust, productive cob structure of modern corn. Explaining this transition is challenging; while some models propose a series of massive mutations, others suggest that hybridization between teosinte and gamma grass may have produced the characteristic cob structure.1
• Preservation Challenges: Plant remains are often small and friable, making them harder to recover and analyze compared to animal remains. While modern techniques like direct radiocarbon dating have improved accuracy, historical reliance on indirect dating methods limited earlier research.2