For other uses, see Population (disambiguation).
The distribution of human world population in 1994.
A population is a summation of all the organisms of the same group or species, who live in the same geographical area, and have the capability of interbreeding.[1][2]
, the population of a certain species in a certain area is estimated using the Lincoln Index. The area that is used to define a sexual population is defined as the area where inter-breeding is potentially possible between any pair within the area. The probability of interbreeding is greater than the probability of cross-breeding with individuals from other areas. Under normal conditions, breeding is substantially more common within the area than across the border.[3]
In sociology, population refers to a collection of human beings. Demography is a social science which entails the statistical study of human populations. This article refers mainly to human population.
Contents
- 1 Population genetics (ecology)
- 2 World human population
- 2.1 Predicted growth and decline
- 2.2 Control
- 3 See also
- 4 Notes
- 5 External links
Population genetics (ecology)
In population genetics a sexual population is a set of organisms in which any pair of members can breed together. This means that they can regularly exchange gametes to produce normally-fertile offspring, and such a breeding group is also known therefore as a gamodeme. This also implies that all members belong to the same of species, such as humans.[4] If the gamodeme is very large (theoretically, approaching infinity), and all gene alleles are uniformly distributed by the gametes within it, the gamodeme is said to be panmictic. Under this state, allele (gamete) frequencies can be converted to genotype (zygote) frequencies by expanding an appropriate quadratic equation, as shown by Sir Ronald Fisher in his establishment of quantitative genetics.[5]
Unfortunately, this seldom occurs in nature : localisation of gamete exchange – through dispersal limitations, or preferential mating, or cataclysm, or other cause – may lead to small actual gamodemes which exchange gametes reasonably uniformly within themselves, but are virtually separated from their neighbouring gamodemes. However, there may be low frequencies of exchange with these neighbours. This may be viewed as the breaking up of a large sexual population(panmictic)into smaller overlapping sexual populations. This failure of panmixia leads to two important changes in overall population structure: (1).the component gamodemes vary (through gamete sampling) in their allele frequencies when compared with each other and with the theoretical panmictic original (this is known as dispersion, and its details can be estimated using expansion of an appropriate binomial equation); and (2). the level of homozygosity rises in the entire collection of gamodemes. The overall rise in homozygosity is quantified by the inbreeding coefficient (f or φ). Note that all homozygotes are increased in frequency – both the deleterious and the desirable! The mean phenotype of the gamodemes collection is lower than that of the panmictic "original" – which is known as inbreeding depression. It is most important to note, however, that some dispersion lines will be superior to the panmictic original, while some will be about the same, and some will be inferior. The probabilities of each can be estimated from those binomial equations. In plant and animal breeding, procedures have been developed which deliberately utilise the effects of dispersion (such as line breeding, pure-line breeding, back-crossing). It can be shown that dispersion-assisted selection leads to the greatest genetic advance (ΔG = change in the phenotypic mean), and is much more powerful than selection acting without attendant dispersion. This is so for both allogamous (random fertilization)[6] and autogamous (self-fertilization) gamodemes[7]
World human population
Main article: World population
As of today's date, the world population is estimated by the United States Census Bureau to be 7.172 billion.[8] The US Census Bureau estimates the 7 billion number was surpassed on 12 March 2012. According to a separate estimate by the United Nations, Earth’s population exceeded seven billion in October 2011, a milestone that offers unprecedented challenges and opportunities to all of humanity, according to UNFPA, the United Nations Population Fund.[9]
According to papers published by the United States Census Bureau,the world population hit 6.5 billion on 24 February 2006. The United Nations Population Fund 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[which?] countries, such as Nigeria, is not even known to the nearest million,[10] so there is a considerable margin of error in such estimates.[11]
Researcher Carl Haub calculated that a total of over 100 billion people have probably been born in the last 2000 years.[12]
Predicted growth and decline
The years taken for every billion people to be added to the world's population, and the years that population was reached. (with future estimates). See also alt. chart
Main article: Population growth
Population growth increased significantly as the Industrial Revolution gathered pace from 1700 onwards.[13] The last 50 years have seen a yet more rapid increase in the rate of population growth[13] due to medical advances and substantial increases in agricultural productivity, particularly beginning in the 1960s,[14] made by the Green Revolution.[15] In 2007 the United Nations Population Division projected that the world's population will likely surpass 10 billion in 2055.[16]
In the future, the world's population is expected to peak,[17] after which 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.[18] Population has already declined in the last decade or two in Eastern Europe, the Baltics and in the Commonwealth of Independent States.[19]
The population pattern of less-developed regions of the world in recent years has been marked by gradually declining birth rates. These followed an earlier sharp reduction in death rates.[20] This transition from high birth and death rates to low birth and death rates is often referred to as the demographic transition.[20]
Control
Main article: Human population 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 with the goal of increasing the rate of population growth. In the period from the 1950s to the 1980s, concerns about global population growth and its effects on poverty, environmental degradation and political stability led to efforts to reduce population growth rates. While population control can involve measures that improve people's lives by giving them greater control of their reproduction, a few programs, most notably the Chinese government's one-child per family policy, have resorted to coercive measures.
In the 1980s, tension grew between population control advocates and women's health activists who advanced women's reproductive rights as part of a human rights-based approach.[21] Growing opposition to the narrow population control focus led to a significant change in population control policies in the early 1990s.[22]
See also
- Community (ecology)
- List of countries by population
- Lists of organisms by population
- Population Europe
Notes
- ^ "Population". Biology Online. Retrieved 5 December 2012.
- ^ "Definition of population (biology)". Oxford Dictionaries. Oxford University Press. Retrieved 5 December 2012. "a community of animals, plants, or humans among whose members interbreeding occurs"
- ^ Hartl, Daniel (2007). Principles of Population Genetics. Sinauer Associates. p. 45. ISBN 978-0-87893-308-2.
- ^ Hartl, Daniel (2007). Principles of Population Genetics. Sinauer Associates. p. 95. ISBN 978-0-87893-308-2.
- ^ Fisher, R. A. (1999). The Genetical Theory of Natural Selection. Oxford University Press. ISBN 0-19-850440-3.
- ^ Gordon, Ian L. (2000). "Quantitative genetics of allogamous F2 : an origin of randomly fertilized populations". Heredity 85: 43–52. doi:10.1046/j.1365-2540.2000.00716.x. PMID 10971690.
- ^ Gordon, Ian L. (2001). "Quantitative genetics of autogamous F2". Hereditas 134 (3): 255–262. doi:10.1111/j.1601-5223.2001.00255.x. PMID 11833289.
- ^ U.S. Census Bureau – World Pop Clock Projection
- ^ to a World of Seven Billion People UNFPA 12.9.2011
- ^ "Cities in Nigeria: 2005 Population Estimates – MongaBay.com". Retrieved 1 July 2008.
- ^ "Country Profile: Nigeria". BBC News. 24 December 2009. Retrieved 1 July 2008.
- ^ Haub, C. 1995/2004. “How Many People Have Ever Lived On Earth?” Population Today, http://www.prb.org/Articles/2002/HowManyPeopleHaveEverLivedonEarth.aspx
- ^ a b As graphically illustrated by population since 10,000BC and population since 1000AD
- ^ "The end of India's green revolution?". BBC News. 29 May 2006. Retrieved 29 November 2009.
- ^ Food First/Institute for Food and Development Policy
- ^ "World population will increase by 2.5 billion by 2050; people over 60 to increase by more than 1 billion" (Press release). United Nations Population Division. 13 March 2007. Retrieved 14 March 2007. "The world population continues its path towards population ageing and is on track to surpass 9 billion persons by 2050."
- ^ World Population Development Statistics: Forecast, United Nations, 2011.
- ^ "The End of World Population Growth". Retrieved 4 November 2008.
- ^ Shackman, Gene, Xun Wang and Ya-Lin Liu. 2011. Brief review of world population trends. Available at http://gsociology.icaap.org/report/demsum.html
- ^ a b http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/P/Populations.html
- ^ Knudsen, Lara (2006). Reproductive Rights in a Global Context. Vanderbilt University Press. p. 2. ISBN 9780826515285.
- ^ Knudsen, Lara (2006). Reproductive Rights in a Global Context. Vanderbilt University Press. pp. 4–5. ISBN 9780826515285.
External links
- UNFPA, The United Nations Population Fund
- United Nations Population Division
- CICRED homepage a platform for interaction between research centres and international organizations, such as the United Nations Population Division, UNFPA, WHO and FAO.
- Current World Population
- NECSP HomePage
- Overpopulation
- Population Matters
- Population Reference Bureau (2005). Retrieved 13 February 2005.
- Population World: Population of World. Retrieved 13 February 2004.
- SIEDS, Italian Society of Economics Demography and Statistics
- United Nations Economic Commission for Europe – Official Web Site
- World Population Counter, and separate regions.
- WorldPopClock.com. (French)
- Populations du monde. (French)
- OECD population data
- Understanding the World Today Reports about world and regional population trends
- Lee, Ronald Demos (2008). "Population". In David R. Henderson (ed.). Concise Encyclopedia of Economics (2nd ed.). Indianapolis: Library of Economics and Liberty. ISBN 978-0865976658. OCLC 237794267.
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Human population
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| Major topics |
- Biocapacity
- Optimum population
- Overpopulation
- Population ethics
- Population momentum
- Sustainable development
- World population
- Zero population growth
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| Biological and related topics |
- Family planning
- Human population control
- One-child policy
- Two-child policy
- Overconsumption
- Pollution
- Population biology
- Population decline
- Population density
- Population dynamics
- Population growth
- Population model
- Population pyramid
- Projections of population growth
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Population
ecology
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- Carrying capacity
- Deep ecology
- Earth's energy budget
- Food security
- Habitat destruction
- I = P × A × T
- Malthusian growth model
- Overshoot (population)
- World energy consumption
- World energy resources
- World3 model
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| Literature |
- A Modest Proposal
- An Essay on the Principle of Population
- How Much Land Does a Man Need?
- Operating Manual for Spaceship Earth
- The Limits to Growth
- The Population Bomb
- The Skeptical Environmentalist
- The Ultimate Resource
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| Publications |
- Population and Environment
- Population and Development Review
- Population and housing censuses by country
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| Lists |
- Metropolitan areas by population
- World population milestones
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Events and
organizations
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- 7 Billion Actions
- International Conference on Population and Development
- Population Action International
- Population Connection
- Population Matters
- United Nations Population Fund
- Voluntary Human Extinction Movement
- World Population Day
- World Population Foundation
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| Related topics |
- Classic Maya collapse
- Fertility and intelligence
- Green Revolution
- Holocene extinction
- US immigration reduction
- Reproductive rights
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Lists of countries by population statistics
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| Population |
- Current population
- Current population (inc. dependent territories)
- Current population (graphical)
- Population in 1900
- Population in 1907
- Population in 2000
- Population in 2010
- Population (United Nations statistics)
- Population growth rate
- natural increase
- past and future population
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| Population density |
- Current density
- Current real density based on food growing capacity
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| (Regional) |
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- Population of national capitals
- Population of cities proper
- Population of urban areas
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| Other Demographics |
- Age at first marriage
- Divorce rate
- Ethnic and cultural diversity level
- Foreign-born population
- Median age
- Net migration rate
- Number of households
- Sex ratio
- Urban population
- Urbanization
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| Health |
- Antiviral medications for pandemic influenza
- Birth rate
- Mortality rate
- Fertility rate
- HIV/AIDS adult prevalence rate
- Infant mortality rate
- Life expectancy
- Obesity
- Percentage suffering from undernourishment
- Health expenditure covered by government
- Suicide rate
- Total health expenditure (PPP) per capita
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| Education and innovation |
- 25-34 year olds having a tertiary education degree
- Bloomberg Innovation Quotient
- Education Index
- International Innovation Index
- Innovation Union Scoreboard
- Literacy rate
- Programme for International Student Assessment
- Progress in International Reading Literacy Study
- Trends in International Mathematics and Science Study
- Women's average years in school
- World Intellectual Property Indicators
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| Economic |
- Development aid given
- Employment rate
- Irrigated land area
- Human Development Index
- by country
- inequality-adjusted
- Human Poverty Index
- Imports
- Income equality
- Job security
- Labour force
- Number of millionaires (US dollars)
- Number of billionaires (US dollars)
- Percentage living in poverty
- Sen social welfare function
- Unemployment rate
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- List of international rankings
- List of top international rankings by country
- Lists by country
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Hierarchy of life
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- Biosphere > Ecosystem > Biocoenosis > Population > Organism > Organ system > Organ > Tissue > Cell > Organelle > Macromolecule > Biomolecule > Atom > Quark
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Ethnicity
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| Related concepts |
- Clan
- Ethnic group
- Ethno-linguistic group
- Ethno-religious group
- Indigenous peoples
- Ingroups and outgroups
- Meta-ethnicity
- Minority group
- Nation
- Nationality
- Panethnicity
- Population
- Race
- Tribe
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| Ethnology |
- Anthropology
- Ethnic studies
- Ethnobiology
- Ethnobotany
- Ethnogeology
- Ethnography
- Ethnolinguistics
- Ethnology
- Ethnomathematics
- Ethnomusicology
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- Ethnotaxonomy
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| Groups by region |
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- Arab League
- Europe
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| Americas |
- Indigenous
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| Asia |
- Central
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- Northern
- South
- Southeast
- West
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Identity and
ethnogenesis
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- Cross-race effect
- Cultural assimilation
- Cultural identity
- Demonym
- Endonym
- Ethnic flag
- Folk religion
- Imagined communities
- Kinship and Descent
- Lineage-bonded society
- Mores
- Myth of origins
- Nation-building
- Nation state
- National language
- National myth
- Pantribal sodalities
- Tribal name
- Tribalism
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| Multiethnic society |
- Consociationalism
- Diaspora politics
- Dominant minority
- Ethnic democracy
- Ethnic interest group
- Ethnocracy
- Ethnopluralism
- Indigenous rights
- Minority rights
- Multinational state
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Ideology and
ethnic conflict
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- Cultural genocide
- Ethnic cleansing (list)
- Ethnic hatred
- Ethnic nationalism
- Ethnic nepotism
- Ethnic stereotype
- Ethnic violence
- Ethnocentrism
- Ethnocide
- Genocide
- Indigenism
- Separatist movements
- Xenophobia
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