Population

The distribution of human world population in 2018
Key

In biology, a population is all the organisms of the same group or species, which live in a particular geographical area, and have the capability of interbreeding.[1][2] The area of a sexual population is the area where inter-breeding is potentially possible between any pair within the area, and where the probability of interbreeding is greater than the probability of cross-breeding with individuals from other areas.[3]

In sociology, population refers to a collection of humans. Demography is a social science which entails the statistical study of human populations. Population in simpler terms is the number of people in a city or town, region, country or world; population is usually determined by a process called census (a process of collecting, analyzing, compiling and publishing data)

This article refers mainly to human population.

Population genetics (ecology)

In population genetics a sex 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 Gamo deme. This also implies that all members belong to the same species.[4] If the Gamo deme is very large (theoretically, approaching infinity), and all gene alleles are uniformly distributed by the gametes within it, the Gamo deme 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]

This seldom occurs in Nature: localization of gamete exchange – through dispersal limitations, preferential mating, cataclysm, or other cause – may lead to small actual Gamo demes which exchange gametes reasonably uniformly within themselves but are virtually separated from their neighboring Gamo demes. However, there may be low frequencies of exchange with these neighbors. 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 Gamo demos 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 Gamo demes. 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 Gamo demes 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 utilize the effects of dispersion (such as line breeding, pure-line breeding, backcrossing). 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) Gamo demes.[7]

In ecology, the population of a certain species in a certain area can be estimated using the Lincoln Index.

Other Languages
Afrikaans: Bevolking
Alemannisch: Bevölkerung
asturianu: Población
azərbaycanca: Əhali
বাংলা: জনসংখ্যা
Bân-lâm-gú: Jîn-kháu
беларуская: Насельніцтва
беларуская (тарашкевіца)‎: Насельніцтва
भोजपुरी: जनसंख्या
български: Население
bosanski: Populacija
brezhoneg: Poblañs
català: Població
Чӑвашла: Халăх йышĕ
Cebuano: Kamulupyohan
čeština: Obyvatelstvo
chiShona: Hugari hwevanhu
Cymraeg: Poblogaeth
dansk: Befolkning
Deutsch: Bevölkerung
eesti: Rahvastik
Ελληνικά: Πληθυσμός
español: Población
Esperanto: Loĝantaro
estremeñu: Puebración
euskara: Biztanleria
فارسی: جمعیت
français: Population
Frysk: Befolking
furlan: Popolazion
Gaeilge: Daonra
galego: Poboación
ગુજરાતી: વસતી
客家語/Hak-kâ-ngî: Ngìn-khiéu
한국어: 인구
հայերեն: Բնակչություն
हिन्दी: जनसंख्या
hrvatski: Stanovništvo
Ilokano: Populasion
Bahasa Indonesia: Penduduk
interlingua: Population
isiXhosa: Ipopulation
íslenska: Mannfjöldi
italiano: Popolazione
עברית: אוכלוסייה
Basa Jawa: Cacah jiwa
ಕನ್ನಡ: ಜನಸಂಖ್ಯೆ
ქართული: მოსახლეობა
kernowek: Doesedh
Kreyòl ayisyen: Popilasyon
kurdî: Gelhe
Кыргызча: Калкы
latviešu: Populācija
Lëtzebuergesch: Bevëlkerung
lietuvių: Populiacija
Ligure: Popolaçion
Limburgs: Bevölking
lingála: Bato
magyar: Populáció
मैथिली: जनसङ्ख्या
македонски: Население
Malagasy: Mponina
მარგალური: მახორობა
Bahasa Melayu: Penduduk
монгол: Хүн ам
မြန်မာဘာသာ: လူဦးရေ
Nederlands: Bevolking
Nedersaksies: Bevolking
नेपाली: जनसङ्ख्या
日本語: 人口
нохчийн: Бахархой
norsk: Befolkning
norsk nynorsk: Folketal
occitan: Populacion
ਪੰਜਾਬੀ: ਵੱਸੋਂ
پښتو: نفوس
português: População
română: Populație
русский: Население
संस्कृतम्: जनसङ्ख्या
Scots: Population
shqip: Popullsia
sicilianu: Pupulazzioni
Simple English: Population
سنڌي: آبادي
slovenčina: Obyvateľstvo
slovenščina: Prebivalstvo
словѣньскъ / ⰔⰎⰑⰂⰡⰐⰠⰔⰍⰟ: Въсєлѥниѥ
српски / srpski: Становништво
srpskohrvatski / српскохрватски: Stanovništvo
Basa Sunda: Populasi
suomi: Väkiluku
svenska: Befolkning
Tagalog: Populasyon
татарча/tatarça: Халык (демография)
తెలుగు: జనాభా
tetun: Populasaun
тоҷикӣ: Аҳолӣ
Türkçe: Nüfus
удмурт: Улӥсьёс
українська: Населення
اردو: آبادی
vèneto: Popołasion
Tiếng Việt: Dân số
文言: 人口
West-Vlams: Bevolkienge
Winaray: Populasyon
Wolof: Way-dëkk
吴语: 人口
粵語: 人口
Zeêuws: Bevolkienge
中文: 人口