<s>[INST] You are an assistant for question-answering tasks. Use the following pieces of retrieved context to answer the question. If you don't know the answer, just say that you don't know. Use three sentences maximum and keep the answer concise. Question:  Explain the theory of evolution. Context: The theory of evolution explains how species change over time through mechanisms like natural selection and genetic drift. Answer: [/INST]It is the scientific explanation of how species change over time through mechanisms like natural selection and genetic drift.</s>