Internal. The ultimate sources of variation, the source of new heritable characteristics in populations and species, are due to mutation and recombination in chromosomes, genes, DNA.
Zone VE is the flood insurance rate zone that corresponds to coastal areas that have additional hazards associated with storm waves. Mandatory flood insurance requirements apply. Zone X and Zone X-500 are flood insurance rate zones that are outside the flood plain or with average flood depths of less than 1 foot.
of flooding. This zone is also used to designate base floodplains of lesser hazards, such as areas protected by levees. from 100-year flood, or shallow flooding areas with average depths of less than one foot or drainage areas less than 1. square mile.