Population

Population

Overview
A population is all the organisms that both belong to the same group or species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...

 and live in the same geographical area. The area that is used to define a sexual
Sex
In biology, sex is a process of combining and mixing genetic traits, often resulting in the specialization of organisms into a male or female variety . Sexual reproduction involves combining specialized cells to form offspring that inherit traits from both parents...

 population is such that inter-breeding is possible between any pair within the area and more probable than cross-breeding with individuals from other areas. Normally breeding is substantially more common within the area than across the border.

In sociology
Sociology
Sociology is the study of society. It is a social science—a term with which it is sometimes synonymous—which uses various methods of empirical investigation and critical analysis to develop a body of knowledge about human social activity...

, population refers to a collection of human
Human
Humans are the only living species in the Homo genus...

 beings.
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Encyclopedia
A population is all the organisms that both belong to the same group or species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...

 and live in the same geographical area. The area that is used to define a sexual
Sex
In biology, sex is a process of combining and mixing genetic traits, often resulting in the specialization of organisms into a male or female variety . Sexual reproduction involves combining specialized cells to form offspring that inherit traits from both parents...

 population is such that inter-breeding is possible between any pair within the area and more probable than cross-breeding with individuals from other areas. Normally breeding is substantially more common within the area than across the border.

In sociology
Sociology
Sociology is the study of society. It is a social science—a term with which it is sometimes synonymous—which uses various methods of empirical investigation and critical analysis to develop a body of knowledge about human social activity...

, population refers to a collection of human
Human
Humans are the only living species in the Homo genus...

 beings. Demography
Demography
Demography is the statistical study of human population. It can be a very general science that can be applied to any kind of dynamic human population, that is, one that changes over time or space...

 is a social science which entails the statistical study of human populations. This article refers mainly to human population.
populations meaning:the total number of people inhabiting a country, city, or any district or area.

Population genetics


In population genetics
Population genetics
Population genetics is the study of allele frequency distribution and change under the influence of the four main evolutionary processes: natural selection, genetic drift, mutation and gene flow. It also takes into account the factors of recombination, population subdivision and population...

 a sexual
Sex
In biology, sex is a process of combining and mixing genetic traits, often resulting in the specialization of organisms into a male or female variety . Sexual reproduction involves combining specialized cells to form offspring that inherit traits from both parents...

 population is a set of organisms in which any pair of members can breed
Breeding in the wild
Breeding in the wild is the natural process of animal reproduction occurring in the natural habitat of a given species. This terminology is distinct from animal husbandry or breeding of species in captivity...

 together. This implies that all members belong to the same species.
.

World human population


As of , the world population is estimated by the United States Census Bureau
United States Census Bureau
The United States Census Bureau is the government agency that is responsible for the United States Census. It also gathers other national demographic and economic data...

 to be billion. Eurek Alert: World Population to surpass 7 Billion in 2011. Earth’s population will reach seven billion on 31 October, a milestone that offers unprecedented challenges and opportunities to all of humanity, according to UNFPA, the United Nations Population Fund.
According to papers published by the United States Census Bureau
United States Census Bureau
The United States Census Bureau is the government agency that is responsible for the United States Census. It also gathers other national demographic and economic data...

, the world population hit 6.5 billion (6,500,000,000) on 24 February 2006. The United Nations Population Fund
United Nations Population Fund
The United Nations Population Fund is a UN organization. The work of the UNFPA involves promotion of the right of every woman, man and child to enjoy a life of health and equal opportunity. This is done through major national and demographic surveys and with population censuses...

 designated 12 October 1999 as the approximate day on which world population reached 6 billion. This was about 12 years after world population reached 5 billion in 1987, and 6 years after world population reached 5.5 billion in 1993. The population of some countries, such as Nigeria
Nigeria
Nigeria , officially the Federal Republic of Nigeria, is a federal constitutional republic comprising 36 states and its Federal Capital Territory, Abuja. The country is located in West Africa and shares land borders with the Republic of Benin in the west, Chad and Cameroon in the east, and Niger in...

, is not even known to the nearest million, so there is a considerable margin of error in such estimates.

Researcher, Carl Haub, calculated that a total of over 100 billion people have probably been born in the last 2000 years.

Growth


]
Population growth
Population growth
Population growth is the change in a population over time, and can be quantified as the change in the number of individuals of any species in a population using "per unit time" for measurement....

 increased significantly as the Industrial Revolution
Industrial Revolution
The Industrial Revolution was a period from the 18th to the 19th century where major changes in agriculture, manufacturing, mining, transportation, and technology had a profound effect on the social, economic and cultural conditions of the times...

 gathered pace from 1700 onwards. The last 50 years have seen a yet more rapid increase in the rate of population growth due to medical advances and substantial increases in agricultural productivity, particularly beginning in the 1960s, made by the Green Revolution
Green Revolution
Green Revolution refers to a series of research, development, and technology transfer initiatives, occurring between the 1940s and the late 1970s, that increased agriculture production around the world, beginning most markedly in the late 1960s....

. In 2007 the United Nations Population Division projected that the world's population will likely surpass 10 billion in 2055.
In the future, world population has been expected to reach a peak of growth, from there it will decline due to economic reasons, health concerns, land exhaustion and environmental hazards. According to one report, it is very likely that the world's population will stop growing before the end of the 21st century. Further, there is some likelihood that population will actually decline before 2100. Population has already declined in the last decade or two in Eastern Europe, the Baltics and in the Commonwealth of Independent States.

The population pattern of less-developed regions of the world in recent years has been marked by gradually declining birth rates following an earlier sharp reduction in death rates. This transition from high birth and death rates to low birth and death rates is often referred to as the demographic transition
Demographic transition
The demographic transition model is the transition from high birth and death rates to low birth and death rates as a country develops from a pre-industrial to an industrialized economic system. The theory is based on an interpretation of demographic history developed in 1929 by the American...

.

Control


Human population control is the practice of artificially altering the rate of growth of a human population. Historically, human population control has been implemented by limiting the population's birth rate
Birth rate
Crude birth rate is the nativity or childbirths per 1,000 people per year . Another word used interchangeably with "birth rate" is "natality". When the crude birth rate is subtracted from the crude death rate, it reveals the rate of natural increase...

, usually by government mandate, and has been undertaken as a response to factors including high or increasing levels of poverty
Poverty
Poverty is the lack of a certain amount of material possessions or money. Absolute poverty or destitution is inability to afford basic human needs, which commonly includes clean and fresh water, nutrition, health care, education, clothing and shelter. About 1.7 billion people are estimated to live...

, environmental concerns
Carrying capacity
The carrying capacity of a biological species in an environment is the maximum population size of the species that the environment can sustain indefinitely, given the food, habitat, water and other necessities available in the environment...

, religious reasons
Religion
Religion is a collection of cultural systems, belief systems, and worldviews that establishes symbols that relate humanity to spirituality and, sometimes, to moral values. Many religions have narratives, symbols, traditions and sacred histories that are intended to give meaning to life or to...

, and overpopulation
Overpopulation
Overpopulation is a condition where an organism's numbers exceed the carrying capacity of its habitat. The term often refers to the relationship between the human population and its environment, the Earth...

. While population control can involve measures that improve people's lives by giving them greater control of their reproduction, some programs have exposed them to exploitation.

Worldwide, the population control movement was active throughout the 1960s and 1970s, driving many reproductive health
Reproductive health
Within the framework of the World Health Organization's definition of health as a state of complete physical, mental and social well-being, and not merely the absence of disease or infirmity, reproductive health, or sexual health/hygiene, addresses the reproductive processes, functions and system...

 and family planning
Family planning
Family planning is the planning of when to have children, and the use of birth control and other techniques to implement such plans. Other techniques commonly used include sexuality education, prevention and management of sexually transmitted infections, pre-conception counseling and...

 programs. In the 1980s, tension grew between population control advocates and women's health activists who advanced women's reproductive rights
Reproductive rights
Reproductive rights are legal rights and freedoms relating to reproduction and reproductive health. The World Health Organization defines reproductive rights as follows:...

 as part of a human rights
Human rights
Human rights are "commonly understood as inalienable fundamental rights to which a person is inherently entitled simply because she or he is a human being." Human rights are thus conceived as universal and egalitarian . These rights may exist as natural rights or as legal rights, in both national...

-based approach. Growing opposition to the narrow population control focus led to a significant change in population control policies in the early 1990s.

See also



  • Crude birth rate
  • Crude death rate
  • Demography
    Demography
    Demography is the statistical study of human population. It can be a very general science that can be applied to any kind of dynamic human population, that is, one that changes over time or space...

  • Life expectancy
    Life expectancy
    Life expectancy is the expected number of years of life remaining at a given age. It is denoted by ex, which means the average number of subsequent years of life for someone now aged x, according to a particular mortality experience...

  • Median age
  • Net migration rate
    Net migration rate
    Net migration rate is the difference of immigrants and emigrants of an area in a period of time, divided per 1,000 inhabitants...

  • Mortality under age 5
  • Net migration
  • Net reproduction rate
    Net reproduction rate
    The net reproduction rate is the average number of daughters that would be born to a female if she passed through her lifetime conforming to the age-specific fertility and mortality rates of a given year. This rate is similar to the gross reproduction rate but takes into account that some females...

  • Nurgaliev's law
    Nurgaliev's law
    In population dynamics, Nurgaliev's law is an equation that describes the rate of change of the size of a population at a given time, in terms of the current population size...


  • Overpopulation
    Overpopulation
    Overpopulation is a condition where an organism's numbers exceed the carrying capacity of its habitat. The term often refers to the relationship between the human population and its environment, the Earth...

  • Population change
  • Population density
    Population density
    Population density is a measurement of population per unit area or unit volume. It is frequently applied to living organisms, and particularly to humans...

  • Population growth rate
  • Rate of natural increase
    Rate of natural increase
    In demographics, the rate of natural increase is the crude birth rate minus the crude death rate of a population. If we neglect the migration, then a positive RNI number means that the population increases and a negative number means that the population decreases.When looking at countries, it...

  • Sex ratio
    Sex ratio
    Sex ratio is the ratio of males to females in a population. The primary sex ratio is the ratio at the time of conception, secondary sex ratio is the ratio at time of birth, and tertiary sex ratio is the ratio of mature organisms....

  • Rural area
  • Urban population
  • World population
    World population
    The world population is the total number of living humans on the planet Earth. As of today, it is estimated to be  billion by the United States Census Bureau...

  • Zero population growth
    Zero population growth
    Zero population growth, sometimes abbreviated ZPG , is a condition of demographic balance where the number of people in a specified population neither grows nor declines, considered as a social aim....


Lists:

Population economics:
  • Demographic economics
    Demographic economics
    Demographic economics or population economics is the application of economics to demography, the study of human populations, including size, growth, density, distribution, and vital statistics.Analysis includes economic determinants and consequences of:...

  • Dependency ratios


Non-human specific:
  • Animal population control
    Animal population control
    Animal population control is the practice of artificially altering the size of any animal population besides humans. It typically refers to the act of limiting the size of an animal population so that it remains manageable, as opposed to the act of protecting a species from excessive rates of...

  • Biological dispersal
    Biological dispersal
    Biological dispersal refers to species movement away from an existing population or away from the parent organism. Through simply moving from one habitat patch to another, the dispersal of an individual has consequences not only for individual fitness, but also for population dynamics, population...

  • Biological exponential growth
    Biological exponential growth
    Biological exponential growth is the exponential growth of biological organisms. When the resources availability is unlimited in the habitat, the population of an organism living in the habitat grows in an exponential or geometric fashion....

  • Overpopulation in companion animals
  • Overpopulation in wild animals
    Overpopulation in wild animals
    Overpopulation in wild animals occurs when a population of a wild species exceeds the carrying capacity of its ecological niche. Overpopulation is a function of the number of individuals compared to the relevant resources, such as the water and essential nutrients they need to survive.In the...

  • Population ecology
    Population ecology
    Population ecology is a sub-field of ecology that deals with the dynamics of species populations and how these populations interact with the environment. It is the study of how the population sizes of species living together in groups change over time and space....



External links