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.
Zone C, Zone X - Areas determined to be outside 500-year floodplain determined to be outside the. 1% and 0.2% annual chance floodplains. Zone B, Zone X500 - Areas of 500-year flood; areas of 100-year flood with average depths of less than 1. foot or with drainage areas less than 1 square mile; and areas protected by levees. from 100-year flood.