I want to know the answer to the following question:
What is the theory that is based on acquired characteristics within a species?
All the background I'm provided with is that "He accepted a version of the inheritance of acquired characteristics (which after Darwin's death came to be called Lamarckism), and Chapter V discusses what he called the effects of use and disuse; he wrote that he thought "there can be little doubt that use in our domestic animals strengthens and enlarges certain parts, and disuse diminishes them; and that such modifications are inherited", and that this also applied in nature.". Is that enough to answer the question?
Answer: yes