What genetic concept is suggested by isolated pockets established after E. sarcitrella is transported via commerce?

Founder effects.

The global spread of *Endrosis sarcitrella* occurs primarily through its successful transport via commerce, where small numbers of individuals hitchhike with stored goods to new continents. When a small founding population establishes itself in a geographically isolated new area, it carries only a subset of the genetic diversity present in the much larger source population. This phenomenon is known as the founder effect. Subsequent evolution in the new location can be rapid because the subsequent population's gene pool is necessarily smaller and potentially unrepresentative of the original diversity, making the population highly susceptible to localized selection pressures present in the new storage environment, such as specific thermal profiles or humidity.