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 AE is the flood insurance rate zone that corresponds with flood depths greater than 3 feet. Mandatory flood insurance purchase requirements apply. Zone AH is the flood insurance rate zone that corresponds to areas of shallow flooding with average depths between 1 and 3 feet.
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.