Corn and Human genetic diversity

As many humans on earth face current interactions with a deadly virus, it is a reminder of significance of genetics and environmental interactions that affects our lives.  Our genetic complexity affects each individual’s ability to defend against the Covid-19 virus but even that is qualified by the multiple individuals medical conditions because of past ‘environments’ and probably genetic changes in the relatively simple virus genes.
 
Human genetic diversity exists because of our evolution under multiple selection pressures of our past environments.  All humans, despite evident, minor visible trait differences such as skin, hair and eye color, have other less evident genetic differences witnessed only by slight differences among an individual family.
 
Corn has a genetic history somewhat similar to humans.  Its ancestor was a related species and perhaps some crossing with another species but with human’s intervention it was moved to multiple environments and selection pressures allowing diversity of characters we could easily see.  Yet, within each environment there was selection for other favored, less easily seen, characteristics.  Just as with human the vast majority of genetics remain close to being identical to others of the species.
 
Corn genetics that were best for desired traits in the season of an individual field in 2020 probably will not be the same as the best hybrid in another field nor even the best for the same farm in 2021. Small differences in 2021 environments will favor slightly different genetics affecting expression of traits not noted in 2020.  Some traits observed in 2020 environments may not be expressed in all environments.  We are dependent on maintaining genetic diversity within the corn species because of environmental variability.
 
Humans also are dependent upon diversity not for those relatively simply inherited characters such as skin, hair and eye color but also for those less obvious genetics that our species successful adaptation to a forever changing environment.  Success of our species, and of corn, is dependent upon genetic diversity.  The biology of both species favors continual genetic interactions and diversity.