Phenotypic variations refer to the observable differences in physical and biological traits among individuals of the same species. These traits can include characteristics such as size, color, shape, and behavior. Variations arise from a combination of genetic factors and environmental influences, leading to diversity within populations. For example, in Darwin's finches, variations in beak size and shape allow different species to adapt to various food sources on the Galápagos Islands. Such adaptations demonstrate how phenotypic variations can enhance survival and reproduction, contributing to the process of natural selection.