As stated in The American Biology Teacher by the eminent scientist Theodosius Dobzhansky (1973), "Nothing in biology makes sense except in the light of evolution." This often-quoted declaration accurately reflects the central, unifying role of evolution in biology. The theory of evolution provides a framework that explains both the history of life and the ongoing adaptation of organisms to environmental challenges and changes.
While modern biologists constantly study and deliberate the patterns, mechanisms, and pace of evolution, they agree that all living things share common ancestors. The fossil record and the diversity of extant organisms, combined with modern techniques of molecular biology, taxonomy, and geology, provide exhaustive examples of and powerful evidence for current evolutionary theory. Genetic variation, natural selection, speciation, and extinction are well-established components of modern evolutionary theory. Explanations are constantly modified and refined as warranted by new scientific evidence that accumulates over time, which demonstrates the integrity and validity of the field.
Scientists have firmly established evolution as an important natural process. The nature of science, experimentation, logical analysis, and evidence-based revision based on detectable and measurable data are procedures that clearly differentiate and separate science from other ways of knowing. Explanations or ways of knowing that invoke metaphysical, non-naturalistic or supernatural mechanisms, whether called "creation science," "scientific creationism," "intelligent design theory," "young earth theory," or similar designations, are outside the scope of science and therefore are not part of a valid science curriculum.
The selection of topics covered in a biology curriculum should accurately reflect the principles of biological science. Teaching biology in an effective and scientifically honest manner requires that evolution be taught in a standards-based instructional framework with effective classroom discussions and laboratory experiences.