is best defined as a sudden variation in an inheritable characteristic, as distinguished from a variation that results from generations of gradual selection.

Mutation

Explanation: Mutation is a change in DNA sequence, it may occur due to error when the DNA is copied or it can arise from various environmental factors such as exposure to chemicals, UV radiation, Highly infectious microbes.

Mutation maybe spontaneous. Acquired mutations occur at some point in a person's life and are present only in certain cells, not in every cell in the body while some may target a tissue, an organ or an entire system.

explanation:

for  example, forests have higher evapotranspiration than other ecosystems,  such  as grasslands, because of their deeper roots and greater leaf area. thus forests have a net moistening effect on the atmosphere and become a moisture source for downwind ecosystems.

you did not attach the discourse, but i assume it to be the discourse on the origin and basis of inequality among men (the original titile in french is: "discours sur l'origine et les fondements de l'inégalité parmi les hommes"), also know as "second discourse". in this discourse, jean-jacques rousseau emphasizes that private property is the basis of all inequalities.

therefore, what enabled the old regime to maintain as long as it did was private property.