Alien826
No religious beliefs
Not if they don't have sex.
With only a handful of exceptions, single-celled organisms reproducing exclusively by simple fission lack one feature that ultimately brings death to all single-cells that have sex, and all multicellular organisms, including human beings: senescence, the gradual, programmed aging of cells and organisms they make up, independently of events in the environment. Accidental cell death was around from the very first appearance of anything we would call life. Death of the organism through senescence ---programmed death----- makes its appearance in evolution at about the same time that sexual reproduction appears.Phd. Biologist William R. Clark, Sex and the Origins of Death, p. 62-63.
Ok, I see. but ...
Bacteria don’t have a fixed lifespan because they don’t grow old. When bacteria reproduce, they split into two equal halves, and neither can be regarded as the parent or the child. You could say that so long as a single one of its descendants survives, the original bacterium does too.
Individual bacteria can also turn themselves into spores with a tough coat to protect themselves from dry conditions. Bacterial spores have been successfully revived from 250-million-year-old salt crystals found in New Mexico in 2000.
But if we assume that the global bacteria population is stable, then it follows that one bacterium must die for each new one that is produced. Bacteria divide somewhere between once every 12 minutes and once every 24 hours. So the average lifespan of a bacterium is around 12 hours or so.
How long does a bacterium live?
www.sciencefocus.com
Bacteria don't grow old, but they do split into two halves to reproduce, so in a sense the original bacterium ceases to exist and two new bacteria appear.