  Motivated by recent research of aging in E. coli, we explore the effects of
aging on bacterial fitness. The disposable soma theory of aging was developed
to explain how differences in lifespans and aging rates could be linked to life
history trade-offs. Although generally applied for multicellular organisms, it
is also useful for exploring life history strategies of single celled organisms
such as bacteria. Starting from the Euler-Lotka equation, we propose a
mathematical model to explore how a finite lifespan effects fitness of
bacteria. We find that that there is surprisingly little loss of fitness when
the bacterium has limited opportunities to reproduce. Instead, the fitness
gained each time the bacteria reproduces decreases rapidly, and investing
resources to survive to reproduce the first few times is likely more
advantageous than investing additional resources to try to maintain cell
integrity longer.
