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.
A Flood Zone is an area which has been carefully studied by the government to determine the probability of flooding due to intensive storms, or along the coast, severe tidal conditions. Flood Zones are designated to specify the probability and frequency of anticipated flood conditions. Flood zones range in severity.