Some otherĪ given age group within the population. Sample of 100 newly-laid eggs, 87 will survive for 4.5 weeks. Table where x = 4.5 weeks and l x = 0.87, this means that from a Whole numbers, l 0 will be equal to the total). L 0, which by definition, equals one (if l x isĮxpressed as a fraction of the total - if l x is expressed in Note that the birth rate can be less than, equalĪ life table gives the probability at birth of beingĪlive at age x (designated as l x). Under optimum conditions (the innate capacity for increase) is symbolized byĪre influencing factors. In nature, a number of factors determine the rate of increase In each stage depends on the overall life history of that species. Live longer can be divided into three ecological periods: pre-reproductive, Note that any influence whichĬhanges the death rate of a population will also affect the birth rate andĪge structure of the population. Overlapping generations and/or which are continuously breeding, tend towardsĪ stable age distribution: the ratio of age groups remains the same as longĪs birth and death rates remain the same. Members of the population are the same age at the same time. In populations of these organisms, nearly all Examples of these would include many herbaceous Some organisms (populations) have annual life cycles with For example, a population of predators affects the Populations are interrelated with populations of Population, including age distribution, population density, populationĭistribution in time and space, the birth rate, the death rate, and the
Each population has characteristics which are unique to that
Is a group of similar individuals of the same kind living in the same area at Life Tables Life Tables Background Definitions