A study using multilocus microsatellite genotyping of 264 maize and teosinte plants challenges the hypothesis of multiple independent domestications of maize. Instead, the results indicate that all maize originated from a single domestication event in southern Mexico about 9,000 years ago. The oldest surviving maize types are from the Mexican highlands, and maize spread across the Americas along two major paths. The phylogenetic analysis supports a model consistent with archaeological evidence suggesting maize diversified in the highlands before spreading to the lowlands. The study also found only modest evidence for postdomestication gene flow from teosinte into maize. Maize, like other crops, was domesticated during a brief period in human history between 5,000 and 10,000 years ago. Previous studies suggested multiple domestications of maize due to its high morphological and genetic diversity. However, this study's comprehensive phylogenetic analysis using 99 microsatellite loci and 264 plants shows that all maize is derived from a single domestication event. The analysis also reveals that maize spread from the highlands to the lowlands, with two major dispersal paths. The study further indicates that gene flow from ssp. mexicana contributed to maize diversity, particularly in highland maize races. The results suggest that the cradle of maize domestication is in the central Balsas River drainage in southern Mexico. The estimated time of domestication is around 9,188 years ago, consistent with archaeological evidence. The study also highlights the importance of further research to resolve the geographic gap between the present-day location of the maize progenitor and the earliest fossil maize cobs. The findings provide a clearer picture of maize's origin and early diversification, emphasizing the role of a single domestication event and subsequent dispersal across the Americas.A study using multilocus microsatellite genotyping of 264 maize and teosinte plants challenges the hypothesis of multiple independent domestications of maize. Instead, the results indicate that all maize originated from a single domestication event in southern Mexico about 9,000 years ago. The oldest surviving maize types are from the Mexican highlands, and maize spread across the Americas along two major paths. The phylogenetic analysis supports a model consistent with archaeological evidence suggesting maize diversified in the highlands before spreading to the lowlands. The study also found only modest evidence for postdomestication gene flow from teosinte into maize. Maize, like other crops, was domesticated during a brief period in human history between 5,000 and 10,000 years ago. Previous studies suggested multiple domestications of maize due to its high morphological and genetic diversity. However, this study's comprehensive phylogenetic analysis using 99 microsatellite loci and 264 plants shows that all maize is derived from a single domestication event. The analysis also reveals that maize spread from the highlands to the lowlands, with two major dispersal paths. The study further indicates that gene flow from ssp. mexicana contributed to maize diversity, particularly in highland maize races. The results suggest that the cradle of maize domestication is in the central Balsas River drainage in southern Mexico. The estimated time of domestication is around 9,188 years ago, consistent with archaeological evidence. The study also highlights the importance of further research to resolve the geographic gap between the present-day location of the maize progenitor and the earliest fossil maize cobs. The findings provide a clearer picture of maize's origin and early diversification, emphasizing the role of a single domestication event and subsequent dispersal across the Americas.