Uploaded February 2025 | Updated September 2026, 3 hours ago
The widely accepted narrative of maize domestication posits a single origin from the wild grass Zea mays ssp. parviglumis (lowland teosinte) in southwest Mexico, likely beginning with de novo mutation at an important gene controlling kernel architecture. However, recent genomic surveys challenge this simplicity, revealing evidence of gene flow from another wild relative, Zea mays ssp. mexicana (highland teosinte). Here we demonstrate widespread hybridization between maize and highland teosinte across time and geography, suggesting a revised model of maize origins in which maize hybridized with teosinte in the central Mexican highlands around 4000 years post-domestication. We also revisit the origin of the important domestication gene tga1, using population genetic analysis and simulations to show that relevant diversity at this key locus likely predated domestication, highlighting the importance of adaptation from pre-existing genetic variation. Together, our findings challenge existing models of maize evolution and illustrate domestication as a complex evolutionary process rather than a single event.
The widely accepted narrative of maize domestication posits a single origin from the wild grass Zea mays ssp. parviglumis (lowland teosinte) in southwest Mexico, likely beginning with de novo mutation at an important gene controlling kernel architecture. However, recent genomic surveys challenge this simplicity, revealing evidence of gene flow from another wild relative, Zea mays ssp. mexicana (highland teosinte). Here we demonstrate widespread hybridization between maize and highland teosinte across time and geography, suggesting a revised model of maize origins in which maize hybridized with teosinte in the central Mexican highlands around 4000 years post-domestication. We also revisit the origin of the important domestication gene tga1, using population genetic analysis and simulations to show that relevant diversity at this key locus likely predated domestication, highlighting the importance of adaptation from pre-existing genetic variation. Together, our findings challenge existing models of maize evolution and illustrate domestication as a complex evolutionary process rather than a single event.
