A variance is an exception to one or more of the zoning restrictions on a piece of property. A variance is different from a nonconforming use, which permits existing structures and uses to continue when zoning is first instituted.
The book, On The Origin Of Species,  suggested  that organisms evolve through the process of natural selection.opulations evolve as the individual organisms less able to survive in the current environment die and fail to reproduce. That is natural selection.
These three ideas seem to run together, so it's important that you are able to distinguish among them. The theory that organisms change over time is evolution. The mechanism b â¦ y which organisms evolve is natural selection. Survival of the fittest explains how natural selection works. Answer = Natural Selection The process of natural selection, of course.opulations evolve as the individual organisms less able to survive in the current environment die and fail to reproduce. That is natural selection.