23 Oral - Platform Session #2 Genetics of Adaptation
Wednesday June 08, 4:30 PM - 4:45 PM

The Population Genetics of Convergent Adaptation in Maize and Teosinte


Authors:
Silas Tittes 1,2; Anne Lorant 3; Sean McGinty 3; John Doebley 4; James Holland 5,6; Jose Sánchez-González 7; Arun Seetharam 8,9; Maud Tenaillon 10; Jeffrey Ross-Ibarra 1,2,11

Affiliations:
1) University of California, Davis, CA; 2) Center for Population Biology, University of California, Davis, CA; 3) Department of Plant Sciences, University of California, Davis, CA; 4) Laboratory of Genetics, University of Wisconsin – Madison, Madison, WI; 5) United States Department of Agriculture – Agriculture Research Service, Raleigh, NC; 6) Department of Crop and Soil Sciences, North Carolina State University, Raleigh, NC; 7) Centro Universitario de Ciencias Biológicas y Agropecuarias, Universidad de Guadalajara, Zapopan, Jalisco; 8) Department of Ecology, Evolution, and Organismal Biology, Ames, IA; 9) Genome Informatics Facility, Iowa State University, Ames, IA; 10) Génétique Quantitative et Evolution - Le Moulon, Université Paris-Saclay, INRAE, CNRS, AgroParisTech, Gif-sur-Yvette, France; 11) Genome Center, University of California, Davis, CA

Keywords:
Natural selection

Evidence for adaptation is ubiquitous, but the geographic scale that it operates over and the forces that moderate the scale are less understood and documented. To study this, we used whole genome sequencing data from sympatric population pairs of cultivated maize and its wild relative teosinte (Zea mays subsp. parviglumis) sampled at six locations across the species' native range. Despite population structure within and between subspecies that could limit the spread of beneficial alleles, our findings suggest that adaptations (as quantified by proportion of mutations fixed by natural selection and signatures of selective sweeps), are frequently shared between multiple populations of maize and teosinte. We found that adaptation is facilitated by the rapid human-assisted migration of cultivated maize, allowing for the exchange of beneficial alleles across the range and between subspecies. Together, our results provide evidence that the geographic scale of adaptation in Zea mays is unexpectedly relatively large when compared to the size of populations.