Purging inbreeding depression and the probability of extinction: full-sib mating

@article{Hedrick1994PurgingID,
  title={Purging inbreeding depression and the probability of extinction: full-sib mating},
  author={Philip W. Hedrick},
  journal={Heredity},
  year={1994},
  volume={73},
  pages={363-372}
}
  • P. Hedrick
  • Published 1 October 1994
  • Biology, Medicine
  • Heredity
Inbreeding depression has been a topic of interest in recent years from a number of perspectives, particularly in the captive breeding of endangered species. Generally, the goal of captive breeding is to avoid the detrimental effects of inbreeding depression and to retain genetic variation for future adaptation. However, an important component of another suggested approach to captive breeding is to purge rapidly the population of its genetic load so that its long-term fitness is not compromised… 
Inbreeding load and purging: implications for the short-term survival and the conservation management of small populations
TLDR
It is found that the minimum effective population size to avoid severe inbreeding depression in the short term is of the order of Ne≈70 for a wide range of species’ reproductive rates.
Inbreeding rate modifies the dynamics of genetic load in small populations
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It is suggested that highly deleterious alleles can be purged in small populations already at low levels of inbreeding, but that purging does not protect the small populations from eventual genetic deterioration and extinction.
Detecting purging of inbreeding depression by a slow rate of inbreeding for various traits: the impact of environmental and experimental conditions.
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Testing assumptions of the efficiency of purging in relation to the inbreeding rate and the experimental conditions for four traits in D. melanogaster finds that for egg-to-adult viability a significant part of the expressed inbreeding depression was effectively purged under slow inbreeding.
Experimental Evolution of the Genetic Load and its Implications for the Genetic Basis of Inbreeding Depression
TLDR
Novel results showing rapid and extensive purging of the genetic load are presented, however, the high rate of extinction of inbred lines, despite the lines being reared in a benign laboratory environment, indicates that intentional purges of the Genetic load of captive endangered species will not be practical due to high rates of subpopulation extinction.
Role of inbreeding depression and purging in captive breeding and restoration programmes
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It is suggested that in small populations there is great uncertainty regarding the success of any single purging event in eliminating inbreeding depression, together with the high likelihood that purging will depress population viability through the fixation of deleterious alleles.
The impact of inbreeding depression on population survival depending on demographic parameters
TLDR
It was concluded that the population survival probability is very sensitive to the carrying capacity, and previous inbreeding should be considered in the case of reintroduction.
The variance in inbreeding depression and the recovery of fitness in bottlenecked populations
  • Kevin Fowler, M. Whitlock
  • Biology, Medicine
    Proceedings of the Royal Society of London. Series B: Biological Sciences
  • 1999
TLDR
The data provide evidence for the possibility of recovery of fitness at two levels, because the average fitness reduction in the F20generation was significantly less than in theF3 generation, and the large variance in inbreeding depression among inbred lines implies that selection within lines has occurred and that selection among them is possible.
Estimation of genetic purging under competitive conditions
TLDR
It is found that competitive fitness declines at a high rate when inbreeding increases in the absence of purging, and in moderate size populations under competitive conditions, inbreeding depression need not be too dramatic in the medium to short term, as the efficiency of purting is also very high.
The Effects of a Bottleneck on Inbreeding Depression and the Genetic Load
TLDR
The effects of a population bottleneck on the inbreeding depression and genetic load caused by deleterious mutations in an outcrossing population is studied and when purging might favor a switch from outbreeding to selfing is examined.
Long-term exhaustion of the inbreeding load in Drosophila melanogaster
TLDR
Computer simulations suggest that the results of two long-term slow inbreeding Drosophila experiments are consistent with a model of relatively few deleterious mutations of large homozygous effects and partially recessive gene action.
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References

SHOWING 1-10 OF 31 REFERENCES
Effects of a change in the level of inbreeding on the genetic load
TLDR
The results show that the genetic load present in an outcrossing population can be explained only with a high mutation rate to partially recessive deleterious alleles, and that inbreeding purges the population of mutant alleles.
INBREEDING DEPRESSION AND ITS EVOLUTIONARY CONSEQUENCES
TLDR
The evidence that the evolution of breeding systems of animals and plants has been significantly influenced by the occurrence of inbreeding depression is reviewed, and the contemporary genetic theory of inmarriage depression and heterosis and the experimental data concerning the strength of in breeding depression are considered.
The Effects of Inbreeding on Isolated Populations: Are Minimum Viable Population Sizes Predictable?
TLDR
The hypothesis that small, isolated populations of Peromyscus mice would show less depression in fitness when inbred than would large, central populations was tested.
Viable Populations for Conservation: Effective population size, genetic variation, and their use in population management
TLDR
It is shown how the effective size of a population, the pattern of natural selection, and rates of mutation interact to determine the amount and kinds of genetic variation maintained.
The effect of linkage and population size on inbreeding depression due to mutational load.
TLDR
It appears that associations between neutral and selected loci may produce effects that differ according to the initial frequencies of the neutral alleles, whereas previous studies have been confined to outbreeding populations, and to alleles at frequencies close to one-half.
Inbreeding and fitness in captive populations: Lessons from Drosophila
TLDR
A reduced mating ability among inbred males of a captive population can have serious consequences for its future sustainability, and can further jeopardize reintroduction efforts; consequently, a program to carefully monitor the reproductive success of individual males, as well as other fitness components, is recommended.
Factors eliminating inbreeding depression in a captive herd of speke's gazelle (Gazella spekei)
TLDR
It is concluded that inbreeding depressions can be rapidly and effectively reduced by an appropriate breeding program, and hence an inbreeding depression does not constitute an insurmountable barrier to the long-term maintenance of a species in which inbreeding cannot be avoided.
Estimates of Lethal Equivalents and the Cost of Inbreeding in Mammals
TLDR
The cost of inbreeding in natural populations of mammals are unknown despite their theoretical importance in genetic and sociobiological models and practical applications in conservation biology, and the regression of juvenile survival on the inbreeding coefficient using pedigrees of 40 captive mammalian populations belonging to 38 species is estimated.
The Effect of Inbreeding on Competitive Male-Mating Ability in DROSOPHILA MELANOGASTER.
TLDR
The results imply that the genetic variation in male-mating ability is largely due to dominance and are consonant with the proposition that intermale sexual selection is a very important component of fitness in D. melanogaster.
MUTATION LOAD AND THE SURVIVAL OF SMALL POPULATIONS
  • M. Lynch, W. Gabriel
  • Biology, Medicine
    Evolution; international journal of organic evolution
  • 1990
TLDR
It is shown that the mean extinction time declines as mutations become more deleterious, and although very small sexual populations, such as self‐fertilized lines, are subject to mutational meltdowns, recombination effectively eliminates the process when the effective population size exceeds a dozen or so.
...
1
2
3
4
...