Some trees are very long-lived, such as the Great Basin Bristlecone Pine and the Giant Sequoia (up to 4,800 years old).
How does natural selection and evolution affect such long-lived organisms? Their DNA has remained unchanged for thousands of years. Mutation can't hope to change the DNA of the entire tree.
I don't understand how they can hope to be able to adapt to a changing environment. And yet the Sequoioideae subfamily has existed since at least the Jurassic, so they must have a winning strategy for survival.
Please help me understand how a species such as this can adapt. And what natural pressure would select for such longevity?