Groundwater supplies drinking water for 51% of the total U.S. population and 99% of the rural population. Groundwater helps grow our food 64% of groundwater is used for irrigation to grow crops. Groundwater is an important component in many industrial processes.
When a lineage splits into multiple line of descents, then, it leads to speciation. It is a process by which a single population evolves into different species. The process of speciation leads to the development of two or more species as the lineages are splitted. These two evolved species are genetically independent.
Hence, the blank can be filled with 'speciation'.
I believe the answer you are looking for has to do with cells, they are the basic building block of life and are the smallest life that can support itself.
I believe they will disappear from the area because they’ll either die from the disease in there food or migrate somewhere else for a different source of food