Archaeological Central American maize genomes suggest ancient gene flow from South America (original) (raw)

Multiproxy evidence highlights a complex evolutionary legacy of maize in South America

Science

Domesticated maize evolved from wild teosinte under human influences in Mexico beginning around 9000 years before the present (yr B.P.), traversed Central America by ~7500 yr B.P., and spread into South America by ~6500 yr B.P. Landrace and archaeological maize genomes from South America suggest that the ancestral population to South American maize was brought out of the domestication center in Mexico and became isolated from the wild teosinte gene pool before traits of domesticated maize were fixed. Deeply structured lineages then evolved within South America out of this partially domesticated progenitor population. Genomic, linguistic, archaeological, and paleoecological data suggest that the southwestern Amazon was a secondary improvement center for partially domesticated maize. Multiple waves of human-mediated dispersal are responsible for the diversity and biogeography of modern South American maize.

The earliest maize from San Marcos Tehuacán is a partial domesticate with genomic evidence of inbreeding

Proceedings of the National Academy of Sciences, 2016

Pioneering archaeological expeditions lead by Richard MacNeish in the 1960s identified the valley of Tehuacán as an important center of early Mesoamerican agriculture, providing by far the widest collection of ancient crop remains, including maize. In 2012, a new exploration of San Marcos cave (Tehuacán, Mexico) yielded nonmanipulated maize specimens dating at a similar age of 5,300–4,970 calibrated y B.P. On the basis of shotgun sequencing and genomic comparisons to Balsas teosinte and modern maize, we show herein that the earliest maize from San Marcos cave was a partial domesticate diverging from the landraces and containing ancestral allelic variants that are absent from extant maize populations. Whereas some domestication loci, such as teosinte branched1 (tb1) and brittle endosperm2 (bt2), had already lost most of the nucleotide variability present in Balsas teosinte, others, such as teosinte glume architecture1 (tga1) and sugary1 (su1), conserved partial levels of nucleotide v...

The Antiquity, Biogeography, and Culture History of Maize in the Americas.

In Histories of Maize: Multidisciplinary Approaches to the Prehistory, Linguistics, Biogeography, Domestication, and Evolution of Maize., edited by John E. Staller, Robert H. Tykot, and Bruce F. Benz., pp. 665-673. , 2006

Histories of Maize in the Americas: Multidisciplinary Approaches

Academic Press, 2006

ABSTRACT This volume reprints 20 chapters from the comprehensive edited volume on the Histories of Maize in the Americas (2006). New findings and interpretations from the past three years have been included. Histories of Maize is the most comprehensive reference source on the botanical, genetic, archaeological, and anthropological aspects of ancient maize published. Included in this abridged volume are new introductory and concluding chapters and updated material on isotopic research. State of the art research on maize chronology, molecular biology, and stable carbon isotope research on ancient human diets have provided additional lines of evidence on the changing role of maize through time and space and its spread throughout the Americas. The multidisciplinary evidence from the social and biological sciences presented in this volume have generated a much more complex picture of the economic, political, and religious significance of maize.