Dark-colored mice from two different populations living hundreds of miles apart were examined. The mice looked nearly identical, but their dark color was caused by two different genes. What does this tell you?

They have a genetic mutation that affects their fur color.

Explanation:

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.