Final answer:
The greatest age reached by a species' population is referred to as its life expectancy, and this number varies based on factors like the age structure and carrying capacity of the environment.
Step-by-step explanation:
The greatest age reached by any member of a given population or species is referred to as its life expectancy. This term considers the average age of death within the population and is used to describe the typical length of life for individuals within that species. When considering population growth and dynamics, researchers look at factors like the age structure, birth rate, and carrying capacity to understand the potential growth or decline of a population. For instance, a population with a greater proportion of individuals in younger age groups is more likely to experience rapid population growth in the future. Additionally, researchers may construct life tables and analyze mortality rates at different age intervals to test hypotheses about the survival challenges faced by the species at various developmental stages. Environmental factors also play a crucial role, as populations tend to level off at the carrying capacity of their environment, which is the maximum number of individuals that can be sustained by the available resources.