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The two halves of U-shaped mortality
Daniel A Levitis1, Daniel E Martínez
1Max-Planck Odense Center on the Biodemography of Aging Odense, Denmark ; Institute of Biology, University of Southern Denmark Odense, Denmark.
Frontiers in Genetics
|March 22, 2013
Summary
Gerontology often overlooks the U-shaped risk pattern, where early-life improvements (ontogenescence) precede late-life decline (senescence). This study challenges common misconceptions about ontogenescence and its relevance to aging research.
Area of Science:
- Biogerontology
- Developmental Biology
- Demography
Background:
- Aging research typically focuses on senescence (age-related decline).
- However, many biological variables show improvements at early ages (ontogenescence) before declining.
- The relationship between these two phases is often oversimplified or misunderstood.
Purpose of the Study:
- To critically evaluate common claims regarding ontogenescence and its relationship with senescence.
- To highlight the importance of considering the U-shaped risk pattern in gerontology.
- To address misconceptions that hinder a comprehensive understanding of aging.
Main Methods:
- Literature review and critical analysis of existing biogerontological claims.
- Examination of mechanistic, demographic, and evolutionary links between ontogenescence and senescence.
- Counterfactual demonstration of specific claims regarding ontogenescence.
Main Results:
- Claim 1 (ontogenescence is purely environmental) is shown to be counterfactual.
- Claim 2 (senescence and ontogenescence are the same phenomenon) is rejected.
- Claim 3 (senescence and ontogenescence are easily separable) is critically assessed.
- Claim 4 (gerontologists can ignore ontogenescence) is refuted.
Conclusions:
- Ontogenescence is a crucial, often neglected, aspect of aging that interacts with senescence.
- A nuanced understanding of both ontogenescence and senescence is vital for advancing gerontology.
- Misconceptions about ontogenescence limit the scope and accuracy of aging research.
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