They do. Evolution. They needed to evolve to reach a certain age ( -> once they cant reproduce anymore) without dying to cancer. https://www.youtube.com/watch?

They do. Evolution. They needed to evolve to reach a certain age ( -> once they cant reproduce anymore) without dying to cancer. https://www.youtube.com/watch?v=fMMPKJFYzdY https://www.youtube.com/watch?v=fMMPKJFYzdY for a more in depth explaination