Pathogen evolution within host individuals as a primary cause of senescence

Area of Science:

• Evolutionary biology
• Gerontology
• Microbiology

Background:

• Senescence, or aging, is a complex process with multiple contributing factors.
• The role of host-pathogen interactions in aging remains incompletely understood.
• Persistent, asymptomatic infections are common in many species.

Purpose of the Study:

• To propose and provide evidence for a novel theory of senescence.
• To explain how pathogen evolution within a host can lead to aging.
• To outline experimental approaches for testing this theory.

Main Methods:

• Review of existing evidence on host-pathogen dynamics.
• Analysis of pathogen replication, variability, and host-specific selection.
• Discussion of experimental designs to validate the proposed theory.

Main Results:

• Evidence suggests asymptomatic individuals harbor persistent viral pathogens.
• These pathogens replicate and exhibit significant variability within hosts.
• Host-specific selection drives pathogen evolution, enhancing host exploitation.
• Evolving infections demonstrably cause progressive host deterioration.

Conclusions:

• Pathogen evolution within the host is a significant, previously underappreciated driver of senescence.
• This evolutionary arms race between host and pathogen contributes to age-related decline.
• Further experimental research is needed to fully elucidate these mechanisms.