  The Lotka-Euler equation is a mathematical expression used to study
population dynamics and growth, particularly in the context of demography and
ecology. The growth rate $\lambda$ is the speed at which an individual produce
their offspring. It is essentially a birth process, and here it is shown that
by reversing the process to a death process, in which individuals die at a rate
$\lambda^{-1}$, the derivation of the Lotka-Euler equation becomes more
intuitive and direct, both in discrete and continuous time.
