Final answer:
Darwin's Theory of Evolution focuses on natural selection and variation within populations leading to evolution, while Neo-Darwinism incorporates genetics and to explain the source of this variation and the heredity of traits. Neo-Darwinism is a modern extension of Darwin's theory, illustrating a more detailed mechanism of evolutionary changes.
Step-by-step explanation:
Darwin's Theory of Evolution is centered on the concept of natural selection, wherein variations within a population allow certain individuals to reproduce more successfully in their environment. These variations occur through mutation and are passed on to the next generation, leading to evolved traits and the diversification of species. The main components of this theory include the observation that all organisms are capable of producing more offspring than the environment can support, there is variation among individuals within a population, and that there is a struggle for existence, which leads to the survival and reproduction of the fittest.
Neo-Darwinism, on the other hand, incorporates modern genetics into Darwin's original theory, including the role of DNA and genetic mutations. While Darwin knew nothing of genetics, Neo-Darwinism explains that mutations in the DNA are the source of genetic variation and that these mutations can be beneficial, neutral, or harmful. Natural selection acts on these mutations, resulting in the evolution of a species. This modern synthesis combines classical Darwinian evolution with Mendelian genetics, providing a more comprehensive understanding of evolution.
Both theories agree on the fundamental principle that species evolve over time and adapt to their environment; however, Neo-Darwinism expands upon the genetic mechanisms that cause these evolutionary changes.