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.
The premise of Darwin's theory of evolution by natural selection is that all life, from mammals to single celled organisms, is related through descent with modification from common ancestral stock. The mechanism he proposed to explain descent with modification was natural selection.he premise of Darwin's theory of evolution by natural selection is that all life, from mammals to single celled organisms, is related through descent with modification from common ancestral stock. The mechanism he proposed to explain descent with modification was natural selection.