The modern rise in life expectancy is one of humanity’s crowning achievements. After more than 200,000 years of slow but steady increases in life expectancy for anatomically modern people like us (McNeill 1976), a new chapter in the book of human longevity began in the middle of the 19 th century when a quantum leap in duration of life began (Omran 1971). The external forces of mortality (e.g., infectious diseases, predation and accidents) that precluded survival beyond the first few years of life for most people were significantly relaxed as modern humans learned how to insulate themselves from the major hazards of the outside world. As a result, the biological consequences of aging are now a common occurrence for the first time in the history of our species. This longevity benefit, however, was accompanied by a trade-off involving a rise in such fatal diseases as cancer, heart disease, stroke and Alzheimer’s disease, as well as such chronic conditions as sensory impairments, arthritis and dementia.