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.
I heard from an insurance expert that the entire Pearland region is a Flood Hazard Zone A, which supposedly designates an area that is at high risk, and that flood insurance is required in the area.any of the areas around Clear Creek are prone more to flood, but the newer developments have built in detention ponds and better drainage systems to reduce risk. I think a lot of the older sections of Pearland are plagued by poor drainage.