Maize Genomics and Genetics 2024, Vol.15, No.2, 80-92 http://cropscipublisher.com/index.php/mgg 85 maize cultivation, which became a central component of their diet and culture. Trade routes such as the Chacoan roads facilitated the movement of maize and agricultural knowledge across the region (Hart and Lovis, 2013). In South America, the spread of maize was influenced by the Andean civilizations, such as the Inca, who developed extensive agricultural terraces and irrigation systems. Maize was a staple crop in the Andean region and was traded extensively, contributing to its spread throughout the continent (Dunn, 1979). 5.3 Environmental and ecological factors influencing the spread Environmental and ecological factors played a critical role in the dissemination of maize. The adaptability of maize to various climatic conditions and its ability to thrive in diverse ecological zones were key factors in its widespread cultivation. Maize's genetic diversity allowed it to be cultivated in a range of environments, from arid regions to high-altitude areas (Tenaillon and Charcosset, 2011). One significant environmental factor was the adaptability of maize to different altitudes and climates. In the highlands of Mexico and the Andes, maize adapted to cooler temperatures and shorter growing seasons. Genetic studies have shown that maize incorporated traits from local teosinte populations, which helped it thrive in these environments (Aguirre-Liguori et al., 2016) Soil fertility and water availability were also crucial in the spread of maize. Regions with fertile soils and reliable water sources, such as river valleys, supported intensive maize cultivation. The development of irrigation systems and agricultural terraces in regions like the Andean highlands further facilitated maize cultivation in areas with less natural water availability (Hart and Lovis, 2013) Additionally, human-induced environmental changes, such as deforestation and land modification for agriculture, created new habitats for maize cultivation. The clearing of forests and the development of agricultural fields expanded the areas where maize could be grown, supporting larger populations and more complex societies. The spread of maize from southern Mexico was facilitated by a combination of proposed routes, cultural and trade exchanges, and environmental factors. These elements collectively contributed to the widespread dissemination and adaptation of maize, making it one of the most important crops in human history. 6 Integration of Genetic and Archaeological Data 6.1 Correlating genetic data with archaeological findings Integrating genetic and archaeological data provides a comprehensive understanding of maize's domestication and spread. Genetic studies offer insights into the evolutionary history and genetic diversity of maize, while archaeological findings provide physical evidence of cultivation and usage patterns. By correlating these data sets, researchers can trace the geographical and temporal pathways of maize dissemination. Genetic evidence indicates that maize was domesticated from its wild ancestor, teosinte, in the Balsas River Valley of southern Mexico around 9 000 years ago (Doebley, 1990). This genetic information aligns with archaeological discoveries of early maize remains at sites such as Guilá Naquitz Cave and San Marcos Cave in Oaxaca, which date back to approximately 6 250 and 4 500 years ago, respectively (Hart and Lovis, 2013). Further genetic analyses show a reduction in genetic diversity during domestication, which corresponds with archaeological evidence of selective breeding and cultivation practices. For example, genetic studies have identified specific alleles in maize that were selected for traits such as increased cob size and kernel number, traits that are evident in the larger, more productive maize cobs found at later archaeological sites (Aguirre-Liguori et al., 2016). 6.2 Case studies showcasing the integration of both data types One notable case study is the integration of genetic and archaeological data from the southwestern United States. Genetic analyses of ancient maize samples from sites such as Bat Cave in New Mexico, dating back to around 3 000 years ago, reveal genetic markers indicative of adaptation to the arid conditions of the region. This genetic information complements archaeological findings of irrigation and dry farming techniques used by the Ancestral Puebloans to cultivate maize (Hart and Lovis, 2013)
RkJQdWJsaXNoZXIy MjQ4ODYzNQ==