Before revision:  Here we discuss how some of the most popular implementations of this machinery assume a strong condition on the ergodicity of the cell cycle duration ensemble and that two common definitions for the term , ergodicity, while identical in an ensemble with a fixed number of individuals , are in fact unique constraints when the ensemble is growing.
After revision:  Here we discuss how some of the most popular implementations of this machinery assume a strong condition on the ergodicity of the cell cycle duration ensemble . We show that one common definition for the term , ergodicity, while identical in an ensemble with a fixed number of individuals , are in fact unique constraints when the ensemble is growing.