Evolution is perhaps the best known but least understood concept by science students.
The purpose of this lesson is to show that a change in organisms has occurred and that this change is the result of 'natural selection'. Overview Scientific theories are unifying explanations for many related observations. Like all scientific theories, the theory of evolution was developed through decades of scientific observation and experimentation. The modern theory of evolution began to take shape as a result of the work of Charles Darwin. Today virtually all scientists recognize evolution as the basis for both the diversity and relatedness of life on Earth.