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.
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.