The Lifespan Limit Debate: Realists vs. Futurists Scientists are generally divided into two camps regarding the limits of human longevity. The "Realists," including demographers and evolutionary biologists like S. Jay Olshansky, argue that the human body has a "biological warranty period". They point out that the dramatic increases in life expectancy seen in the 20th century—largely driven by curing childhood and infectious diseases—have slowed significantly. Realists posit that the human lifespan is naturally capped around 115 to 125 years, and that modern medicine is currently just "manufacturing survival time" by treating the symptoms of age-related decay rather than halting the biological clock.

Conversely, "Futurists" and prominent geneticists, such as Harvard’s David Sinclair, believe that the first person to live to  ...