Ageing and immortality

Area of Science:

• Evolutionary Biology
• Gerontology
• Demography

Background:

• The force of natural selection explains the evolution of ageing.
• A period of late-life immortality, where mortality rates plateau, remains unexplained.
• Existing theories include cohort heterogeneity and a plateau in the force of natural selection.

Purpose of the Study:

• To investigate the biological mechanisms behind late-life immortality.
• To differentiate between two primary theories explaining mortality plateaus in later life.
• To understand the interplay between development, ageing, and immortality in life-history evolution.

Main Methods:

• Comparing survival data between more and less robust ageing cohorts.
• Fitting survival data to mathematical models to test heterogeneity.
• Manipulating the force of natural selection in laboratory populations to observe effects on mortality plateaus.

Main Results:

• The study proposes testable hypotheses for two competing theories of late-life immortality.
• Methodologies are outlined for empirical testing of these theories.
• Potential for significant insights into life-history evolution is highlighted.

Conclusions:

• Late-life immortality presents a significant puzzle in evolutionary biology.
• Testing cohort heterogeneity and selection force plateaus can elucidate this phenomenon.
• This research is crucial for understanding the complete life-history spectrum from development to potential immortality.