Aging is malleable. We think this may be true today, but for most of human history it seemed completely implausible. Aging has always been one of the fixed constants of life. So what has changed?

There has been a scientific revolution in the field of ageing. In fact, we now have a field of aging biology where we didn’t before. The field started in the 1930s, when scientists discovered that eating less could help rats live longer. In the 1980s and 1990s, Tom Johnson and Cynthia Kenyon discovered genes that could control aging in the tiny C. elegans worm. We now know some of those genes, when changed in the same way in flies and mice, can make them also live longer. The previous decades of scientific progress show that we can manipulate aging in different worms, flies and mice, in ways that can translate across the species barrier.