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.
While flood insurance is optional in moderate to low risk zones, it is mandatory for high-risk properties in communities participating with the NFIP. High-risk zones are designated with the letter A and further broken down into the following classifications: