This isn't about what any person wants, it's about what's more likely to increase odds for survival. Living too long, for a creature that doesn't have any medi

This isn't about what any person wants, it's about what's more likely to increase odds for survival. Living too long, for a creature that doesn't have any medical technology, means probably a higher chance of cancer. Living too short means less chance to pass on its genes, or to help its children pass on their genes. So theoretically, we humans found a balance between the two where we live long enough to be grandparents but that's it, and that's what's encoded in our DNA. However, now that we understand DNA better, and also what causes various cancers and how to treat them, we should be able to change our DNA to extend lifespans without causing us to die of cancer at young ages.