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.
Studies suggest that random mutations that individually have no effect on an organism can fuel the emergence of complexity in a process known as constructive neutral evolution. The human eye, Darwin argued, could have evolved from a simple light-catching patch of tissue of the kind that animals such as flatworms grow today. Natural selection could have turned the patch into a cup that could detect the direction of the light. Then, some added feature would work with the cup to further improve vision, better adapting an organism to its surroundings, and so this intermediate precursor of an eye would be passed down to future generations.