How are changes in hox genes significant in the evolution of species?

Hox genes help lay out the basic body forms of many animals, including humans, flies, and worms. They set up the head-to-tail organization. Small changes in such powerful regulatory genes, or changes in the genes turned on by them, could represent a major source of evolutionary change.

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Explanation:

affects the water bodies: excessive use of fertilizers causes eutrophication. the fertilizers which are used on plants affect the quality of land on which it is used, further causing erosion of soil. the fertilizers used on plants contain harmful chemical fumes which affect the environment.