Because through natural selection, only the fittest survive. when the fittest come together and reproduce then the species continues and evolves with only the fittest and strongest genes.
Answer:
Excessive nutrients from fertilizer run off.
Explanation:
Scientists have suspected that phytoplankton blooms might be connected to agricultural run-off. They got some evidence from a recent study by comparing the timing of irrigation along the west coast of Mexico and phytoplankton blooms in Mexico’s Sea of Cortez. During the comparison, they had found a close correlation. Phytoplankton blooms occurred in the Sea of Cortez shortly after the irrigation. This happened because of carried fertilizers after irrigation and other agricultural run-offs into the sea.
The bloom detected in the Gulf of Mexico on December 13 might be similarly linked to agricultural run-off.
They often respond to Quorum sensing which is determined by the cell density. Bacteria cells secrete molecules that can be detected by other bacteria, Quorum sensing allows bacteria to sense the concentration of these signalling molecules to monitor the local density of cells. It used by bacteria to coordinate certain behaviors , such as the production of biofilms.
The answer is:
Community Diversity.
Reason Why: Here is an example, say you have 2 communities, community 1 is A, and community 2 is B, Communities A and B contain 5 tree species, However because community B has greater species evenness it has greater species diversity.
Community A is dominated by one of its 5 species and so has lower species diversity than.....community B, which has the same 5 species but in equal proportion.
Richness- Number of Species
Evenness-Relative abundance.
Hope This Helped!