Aging occurs at the cellular level. When cells have finished their proliferative life span in vitro, and reached a terminal state, the cells are called senescent cells. In the 1960’s, Leonard Hayflick and Paul Moorhead discovered normal human cells divide approximately fifty times, before becoming senescent. More recently, scientists have proposed differing theories of aging and senescent cells, relating to failure of the energy-making capacity of the cells.  Immortal pathogens interfere with the energy making capacity of the cell; and as immortal pathogens proliferate and become chronic, the energy making capacity of a greater number of cells is damaged.

The Neanderthal and Denosovans cultures disappeared from earth, more than 40,000 years ago. Science knows both cultures were heavily infected with pathogens and “viroids” (smallest known infectious pathogens, and likely remnants of immortal pathogens). Today, animal species with a high burden of infectious disease are going extinct. The koalas are highly infected with immortal pathogens, harming fertility and limiting lifespan; and putting the koala at risk of extinction. Tasmanian devils are heavily infected with immortal pathogens, transmit an aggressive form of cancer when they bite each other, and are also at risk of becoming extinct.

The greater the number of different immortal pathogens, the higher the infectious burden, and the longer the chronic infections persist, the faster and more likely aging and a chronic disease will develop.