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.
A flood zone is an area designated on a Flood Hazard Boundary Map. These geographical areas are given a specific rating depending on the estimated flood risk. A flood zone will determine how much flood insurance will cost, and whether or not it is mandatory to carry flood insurance.