Researchers talk about the basis for animal longevity at the Post-Gazette: "What is it about tortoise biology that makes them so long-lived? The same thing can be asked of some even more intriguing creatures in the Methuselah Club, including the rough-eye rockfish (up to 205 years), the bowhead whale (211 years) and the ocean quahog clam (225 years). ... In the bowhead whales, researchers have been able to chart the slow change in the orientation of amino acids in their eyelids, he said, while the rockfish and quahog lay down age-related rings, the rockfish in an ear bone and the quahog on its shell. ... Dr. de Magalhaes said he did a survey two years ago of hundreds of species of mammals, and 'what we showed is there is really no correlation between metabolic rate and life span in mammals.' ... 'I'm a little bit skeptical about the idea that telomeres contribute that much to aging,' said Dr. de Magalhaes, given the fact that mice, which live about four years, have longer telomeres than humans. ... scientists have been able to create mice with short telomeres and with long telomeres, and 'the mice with long telomeres don't have a significant difference in life span.' Unfortunately, the article doesn't delve into mitochondrial biochemistry, which looks like it might be much of the root of differences in life span, in mammals at least.