The members of a population use the same resources in the same ways, so they eventually compete with one another as the population approaches its carrying capacity. Instead of competing for a limiting resource, members of a species may compete indirectly for social dominance or for territory. Competition within a population is part of the pressure of natural selection. A territory is an area defended by one or more individuals against other individuals. The territory is of value not only for space, but for the shelter, food, or breeding sites it contains. Many organisms expend a large amount of time and energy competing with member of the same species of mates, food or homes for their families. Two Types of Population Regulation Population size can be limited in ways that may or may not depend on the density of the population. Causes of death in a population may be related to density dependent, or density independent factors. Population Regulation When a cause of death in a population is density dependent deaths occur more quickly in a crowded population than in a sparse population. This type of regulation happens when individuals of a population are densely packed together. Limited resources, predation, and disease result in higher rates of death in dense populations than in sparse populations. When a cause of death is density independent, a certain proportion of a population may die regardless of the population density. This type of regulation affects all populations in a general uniform way. Severe weather and natural disasters are often density independent causes of death. Ticket out the Door: What is a population? What is density? What is dispersion?
The members of a population use the same resources in the same ways, so they eventually compete with one another as the population approaches its carrying capacity. Instead of competing for a limiting resource, members of a species may compete indirectly for social dominance or for territory. Competition within a population is part of the pressure of natural selection. A territory is an area defended by one or more individuals against other individuals. The territory is of value not only for space, but for the shelter, food, or breeding sites it contains. Many organisms expend a large amount of time and energy competing with member of the same species of mates, food or homes for their families. Two Types of Population Regulation Population size can be limited in ways that may or may not depend on the density of the population. Causes of death in a population may be related to density dependent, or density independent factors. Population Regulation When a cause of death in a population is density dependent deaths occur more quickly in a crowded population than in a sparse population. This type of regulation happens when individuals of a population are densely packed together. Limited resources, predation, and disease result in higher rates of death in dense populations than in sparse populations. When a cause of death is density independent, a certain proportion of a population may die regardless of the population density. This type of regulation affects all populations in a general uniform way. Severe weather and natural disasters are often density independent causes of death. Ticket out the Door: What is a population? What is density? What is dispersion?
Ch%208%20Populations%20-%20specialized%20notes%20-%20Dion%202016.docx