Final answer:
When a population is made up mostly of individuals past reproductive age, the population will gradually decrease due to lack of reproduction. A balance in age groups is necessary for population stability.
Step-by-step explanation:
When a population is made up mostly of individuals that are past reproductive age, the population will gradually decrease over time. This is because these individuals are no longer able to reproduce and contribute to the growth of the population. As a result, the population will experience negative population growth and eventually decline.
For example, let's consider a population of deer where a large portion of the population consists of older deer that are no longer capable of reproduction. Since new offspring are not being produced to replace the older individuals, the population will slowly diminish.
It is important for a population to have a balance of individuals across different age groups to maintain a stable population size and avoid decline.
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