Final answer:
Survivorship curves and life tables are tools that help to understand the patterns of survival and mortality within a population, displaying the proportion of surviving individuals across different age intervals or sexes.
Step-by-step explanation:
Survivorship curves and life tables are essential tools in population ecology, providing deep insights into the survival patterns of different species. Survivorship curves graphically represent the number of individuals surviving at each age interval versus time, highlighting three types of survival patterns—Type I, Type II, and Type III survivorship. A Type I curve indicates low mortality in early life and high mortality in older age groups, often associated with species that produce fewer offspring with higher parental care. Type II curves depict a relatively constant mortality rate throughout the life of the species, characteristic of some bird populations. Finally, Type III curves show high mortality in the early stages and lower mortality rates for those reaching mature age, common in organisms such as trees and marine invertebrates that produce a large number of offspring but provide minimal care.
Life tables further detail these patterns by dividing a population into age groups and sexes, displaying the probability of death before the next birthday, the mortality rate within each age interval, and the life expectancy of individuals. They are crucial for understanding the relative fitness of individuals within a population, which is the individual's ability to survive and reproduce relative to others. These tables can be based on a variety of data, such as the number of individuals born and died within a time period for different age groups or sexes.