To explain: Whether all the individuals in the population have the same adaptive trait after many generations.
Concept introduction: Evolution has resulted in difference between different organisms and their ancestors and the differences among different species. Adaptation is a process by which the organisms best suited or adapted to the environment will survive, reproduce, and can transmit to the next generations, while the others undergo extinction. An adaptive trait is also known as a heritable trait that helps to enhance the fitness of an individual. The fitness is a degree of adaptation to a particular environment, and it is calculated by the individual’s ability to transmit the genetic contributions to their offspring.
Charles Darwin was the first to propose the theory of evolution by natural selection. Natural selection is a process where an organism survives an adverse condition by adapting to it. Natural selection does not produce new alleles in organisms but is a process taken place after the organisms undergo mutation to adapt to that environment.