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The Population Reference Bureau (PRB) Country ranking and comparison by TFR: 1970 and 2013 list is sourced and based on the data of the 2014 World Population Data Sheet, [14] which was published online. [15] [16] Forecast/prediction ranking lists: The UN ranking list is sourced from the United Nations World Population Prospects. Figures are ...
Inbreeding is also used to reveal deleterious recessive alleles, which can then be eliminated through assortative breeding or through culling. In plant breeding, inbred lines are used as stocks for the creation of hybrid lines to make use of the effects of heterosis. Inbreeding in plants also occurs naturally in the form of self-pollination.
A 2023 map of countries by fertility rate. Blue indicates negative fertility rates. Red indicates positive rates. The total fertility rate (TFR) of a population is the average number of children that are born to a woman over her lifetime, if they were to experience the exact current age-specific fertility rates (ASFRs) through their lifetime, and they were to live from birth until the end of ...
Therefore, just as with the mixed mating model, in the effective selfing model there is only one parameter to be estimated. However this parameter, termed the effective selfing rate, is often a more accurate measure of the proportion of self-fertilisation than the corresponding parameter in the mixed mating model. [1] [2]
The effective population size (N e) is the size of an idealised population that would experience the same rate of genetic drift as the real population. [1] Idealised populations are those following simple one-locus models that comply with assumptions of the neutral theory of molecular evolution.
Darwin's wife, Emma, was his first cousin, and he was concerned about the impact of inbreeding on his ten children, three of whom died at age ten or younger; three others had childless long-term marriages. [16] [17] [18] Humans do not seek to completely minimize inbreeding, but rather to maintain an optimal amount of inbreeding vs. outbreeding.
Mixed mating systems are generally characterized by the frequency of selfing vs. outcrossing, but may include the production of asexual seeds through agamospermy. [2] The trade offs for each strategy depend on ecological conditions, pollinator abundance and herbivory [ 3 ] and parasite load. [ 4 ]
The concept of F-statistics was developed during the 1920s by the American geneticist Sewall Wright, [1] [2] who was interested in inbreeding in cattle. However, because complete dominance causes the phenotypes of homozygote dominants and heterozygotes to be the same, it was not until the advent of molecular genetics from the 1960s onwards that ...