["How were the Jain scriptures initially passed down?", "What are the Jain scriptures collectively known as?", "Who typically undertakes the practice of Sallekhana?", "What is the purpose of Sallekhana, according to the context?", "According to Jain tradition, what is Mahavira's position in the series of Tirthankaras?", "Who is often credited as the founder of Jainism?", "What is the archaeological evidence suggesting about the existence of Jain ideas and practices?", "What is the controversial practice mentioned in the context?", "When did Parshvanatha, Mahavira's predecessor, live?"]