haldane_1937
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| - | Haldane, J. B. (1937). The effect of variation of fitness. //The American Naturalist//, | + | ====Haldane 1937==== |
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| + | Haldane, J. B. S. (1937). The effect of variation of fitness. //The American Naturalist//, | ||
| Links | Links | ||
| * https:// | * https:// | ||
| + | * {{private: | ||
| Abstract: In a species in equilibrium variation is mainly due to two causes. Some deleterious genes are being weeded out by selection at the same rate as they are produced by mutation. Others are preserved because the heterozygous form is fitter than either homozygote. In the former case the loss of fitness in the species is roughly equal to the sum of all mutation rates and is probably of the order of 5 per cent. It is suggested that this loss of fitness is the price paid by a species for its capacity for further evolution. | Abstract: In a species in equilibrium variation is mainly due to two causes. Some deleterious genes are being weeded out by selection at the same rate as they are produced by mutation. Others are preserved because the heterozygous form is fitter than either homozygote. In the former case the loss of fitness in the species is roughly equal to the sum of all mutation rates and is probably of the order of 5 per cent. It is suggested that this loss of fitness is the price paid by a species for its capacity for further evolution. | ||
| Takeaway: Haldane considers the effects of deleterious mutations. Estimates are given for mutation-selection equilibrium allele frequencies and average reduction of fitness in the population. Fitness reduction is only a function of, and proportional to, mutation rates. The average individual in a population has a fitness that is a small fraction of the maximum theoretically possible if the genome were free of deleterious mutations. | Takeaway: Haldane considers the effects of deleterious mutations. Estimates are given for mutation-selection equilibrium allele frequencies and average reduction of fitness in the population. Fitness reduction is only a function of, and proportional to, mutation rates. The average individual in a population has a fitness that is a small fraction of the maximum theoretically possible if the genome were free of deleterious mutations. | ||
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| ===Notes=== | ===Notes=== | ||
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| - | Mutated copies are removed by selection each generation ($1-f$ survive). | + | Mutated copies are removed by selection each generation ($f$ survive). |
| $$N x (1-f) $$ | $$N x (1-f) $$ | ||
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| ==Multiple Loci== | ==Multiple Loci== | ||
| - | Assuming mutations are independent both in occurrence and in fitness effects the average individual in the population has an expected fitness of | + | Pages 345--346 describe the predictions over all loci in the genome. |
| $$F = \prod_i (1-m_i)$$ | $$F = \prod_i (1-m_i)$$ | ||
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| ==Other things== | ==Other things== | ||
| - | Haldane discusses the effects of inbreeding and sex-linkage on these prediction and goes through quite a bit of detail | + | Haldane discusses the effects of inbreeding and sex-linkage on these prediction and goes through quite a bit of additional logical details |
haldane_1937.txt · Last modified: 2019/09/16 03:35 by floyd
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