Historical Lifespan Patterns

Higher p increases survival after senescence, making death occur later even when senescence begins earlier. The senescent Penna model shows a greater probability of living to higher ages but not an increase in mean lifespan for higher p. Higher p produces younger populations in terms of senescence onset. Maximum lifespan remains fixed at l_max + M for populations with the same M. The observed lifespan pattern resembled prior genealogy and national-statistics lifespan graphs, supporting the plausibility of the WikiTree data. Among U.S.-born people surviving past age 10, median lifespan around 1650 was about 62 years for both males and females. Average lifespan for U.S.-born females increased sharply from 1850 to 1900. Historical trends showed fewer early deaths and increasing lifespans over time. Increasing M moves senescence onset earlier while allowing longer post-senescence survival.