<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:  Provide an overview of the theory of evolution. Context: The theory of evolution posits that species change over time through natural selection, adaptation, and genetic variation. Answer: [/INST]It posits that species change over time through natural selection, adaptation, and genetic variation.</s>