Evolution and Adaptation in the Maize Genome

Maize (Zea mays ssp. mays) has been a prime model organism for understanding the processes of domestication and adaptation. During domestication, maize underwent drastic morphological changes that differentiate it from its teosinte progenitor such as reduced tillering and seed shattering and freeing of the grain from a stony fruit case. Likewise, post-domestication adaptation to new environments has allowed maize to expand to a distribution far exceeding its wild relatives and in fact to a greater range than any other domesticate. Previous work using traditional top-down approaches, such as quantitative trait locus mapping and genome-wide association, has been successful in identifying canonical candidates for domestication and adaptation. However, the recent availability of genomic data and development of new analytical tools offer the opportunity to increasingly look at these processes from the bottom-up based on genomic signatures of selection. Here we review progress thus far in genomic research of maize domestication and adaptation. We discuss the insights genomics has shed on our understanding of these processes and conclude with a future outlook for how genomics might be further applied to these fields.