Question

1/ Could you think of a way to change the parameters in the life table, so that λ will never stabilize to a certain value? (Hint: a simple way to do so involves changing the values of mx).

2/ Among all the assumptions for the exponential growth model, which no longer hold true for the age-structured model?

Answer 1

2) The assumptions of the exponential growth equation are:

1. No immigration or emigration.
2. Constant birth and death rate.
3. No variation among individuals in genetics, size, or age
4. No time lags

All individuals are similar, an important assumption that they assume . That permit us to focus on the total population size (N) only and differences must be ignored among individuals. Although, individuals are hardly similar. Most animal population include two sexes. And, survival as well as reproduction generally changes with age. Very frequently, low survival for new individuals as for adults. And to have prereproductive juvenile stage is very common for organisms, and clearlyly no offspring can be produced by these individuals. all these differences between individuals direct to keep course of animals with various ages in order to get an exact measure of the growth potential of populationl.

To recognise the growth of age-structured populations, it is essential to know the change of survival and fecundity with age of an individual. That means it is essential to recognise the age, sex, as well as reproductive status of all individuals.