Final answer:
Darwin's theory of evolution is characterized by natural selection, adaptation, common descent, and variation. It illustrates how species evolve through differential survival and reproduction of individuals with advantageous traits. This theory greatly influenced psychology by providing a framework for understanding behavior in terms of evolutionary adaptations.
Step-by-step explanation:
The major features of Darwin's theory of evolution include the concepts of natural selection, common descent, gradualism, and variation among species. According to Darwin, species evolve over time due to the differential survival and reproduction of individuals with advantageous traits, which are then passed on to future generations. This process is termed natural selection. Adaptation occurs when traits that provide a survival or reproductive advantage become more common in a population over time due to this selective process.
Convergent evolution refers to the process where unrelated species develop similar traits due to occupying similar environments or ecological niches, while divergent evolution involves one species diverging into multiple descendant species. Examples supporting evolution by natural selection include the diversity of beak shapes among Galápagos finches, which have adapted to different food sources in their environments.
Darwin's theory had a strong influence on psychologists because it provided a scientific framework for understanding behavior through the lens of adaptation and survival. It informed areas such as comparative psychology, the study of animal behavior, and evolutionary psychology, which considers psychological traits as adaptations just like physical traits.