A recent preprint introduces an alternative angle to an aged query: shifting the focus from “How long did ancient people live?” to “What was the potential maximum lifespan for them?”. Employing epigenetic “clocks” that track age-related shifts in DNA methylation, the researchers put forward the idea that contemporary humans might possess a considerably higher biological ceiling compared to our extinct cousins, Neanderthals and Denisovans. Should their computations be validated, extended human longevity could represent a comparatively recent evolutionary trait of Homo sapiens, rather than something inherited from earlier lineages.
This research, currently shared on Research Square but awaiting peer review, also touches upon a separate contemplation: even if an organism possesses the inherent capability for exceptional longevity, does modern living—with its stressors, ailments, societal disparities, and environmental factors—actually permit many individuals to reach such an advanced age? This tension forms the crux of contemporary debates surrounding “lifespan limits.”
The investigative team (originating from the Institute of Zoology, Chinese Academy of Sciences, alongside other bodies) compiled 15,283 methylation samples spanning individuals from birth up to 114 years old, which included 219 samples from people over 90. They ran 16 methylation clocks across various tissues to gauge the theoretical upper boundary for modern human lifespan.
While epigenetic clocks are widely utilized to gauge biological age, the authors urge caution regarding caveats: the precision of these clocks can diminish during extreme ages, and different tissues exhibit varying rates of “aging.” Nevertheless, by contrasting several methodologies instead of relying on a solitary clock, they maintain their estimate offers at least a plausible range for the biological limit.
Through their modeling approaches, the researchers establish a theoretical maximum lifespan for modern humans somewhere between 128 and 202 years. They also point out that the highest confirmed recorded lifespan remains at 122.493 years (the celebrated record held by Jeanne Calment), indicating their calculated ceiling is proposed not as a “typical” lifespan, but as the absolute extreme boundary.
This demarcation is crucial because demographers and biologists remain divided on whether human lifespan is approaching a hard limit or merely entering a phase where further gains become sparse and statistically sluggish. A 2022 study in Nature illustrates how this contention often hinges on small datasets of supercentenarians and complex issues surrounding record verification.
The same methylation-based logic was subsequently applied to reconstructed methylation maps from an Altai Neanderthal and a Denisovan. The estimated lifespans calculated were 38.2–64.5 years for Neanderthals and 40.0–69.8 years for Denisovans. This is roughly “two decades longer” than some projections based on fossil evidence, yet still substantially below the ultimate lifespan proposed in the preprint for modern humans.
The authors argue that this disparity suggests significantly extended life expectancy is a derived characteristic unique to the modern human lineage, emerging after their divergence from these archaic relatives. This finding does not imply that very old Neanderthals or Denisovans were impossible, but rather that the prerequisite biological conditions for sustained lifespan extension may not have been present to the same degree.
Even granting that archaic humans occasionally might have reached advanced adulthood, surviving long enough to appear “old” within the paleontological record presents a separate challenge. Life in deep antiquity was perilous, and low life expectancy at birth frequently reflects high infant mortality rather than an unalterable law dictating that adults expired at 30 or 35.
For Neanderthals, developmental and mortality patterns likely dictated which age brackets were commonly present in a given area, and consequently, which groups were most likely to fossilize and be discovered. Other research suggests a faster rate of childhood development, potentially linked to the harsh living conditions of the Pleistocene.
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