Generation time is a quantity used in population biology and demography to reflect the relative size of intervals of offspring production. Generation time usually expresses the average age of breeding females within a population. In epidemiology, it is defined as the interval of time between receipt of infection by a host and maximal infectivity of that host. Suppose females begin breeding at age and stop breeding (or die) at age, then the average age of first reproduction of a cohort of females is
where is the hazard function and is the fecundity of females aged .
When the population is in stable age distribution, we can express the generation time as the average age of mothers of zero-year-olds:
where is the Malthusian parameter of the population.
Famous quotes containing the words generation and/or time:
“There is such a thing as food and such a thing as poison. But the damage done by those who pass off poison as food is far less than that done by those who generation after generation convince people that food is poison.”
—Paul Goodman (19111972)
“Dear, why should you command me to my rest,
When now the night doth summon all to sleep?
Methinks this time becometh lovers best;
Night was ordained together friends to keep.
How happy are all other living things,
Which though the day disjoin by several flight,
The quiet evening yet together brings,
And each returns unto his love at night.”
—Michael Drayton (15631631)