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Genetic Status of Atlantic Salmon in Maine Interim Report from the Committee on Atlantic Salmon in Maine (2002) / Chapter Skim
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5 Quality of Data
Pages 37-45

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From page 37...
... However, unlike organisms with nonoveriapping generations, those with overlapping generations have a demographic age structure with the following features: (1) the total population is made up of individuals that belong to different age classes; (2)
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From page 38...
... Moreover, there is a tendency for temporal correlation in the overlapping generation population; allele frequencies tend to fluctuate in a cyclical fashion that is not expected when generations are discrete. Clearly, population size is not the only determinant of the amount of temporal allele- frequency change when generations overlap, because the total population does not represent a single genetically homogeneous unit.
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From page 39...
... Conversely, the observation of statistically significant differences should not automatically be viewed as evidence of gene flow, natural selection, nonrandom sampling (say of family groups) , or an alarmingly small effective population size (Waples 1989, Ryman 1997~.
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From page 40...
... The initial allele frequency is p = A: (a) total population results (and those for age class 1 of the model with overlapping generations)
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From page 41...
... . The total area of coverage can be large, but if fish within the treated area have a higher probability of being close relatives than a random draw of fish from the total population, any interpopulation measure of genetic divergence will be increased.
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From page 42...
... An intriguing question is whether the current (politically delimited) regions make optimal biological sense and whether the management of Maine, New Brunswick, and Nova Scotia salmon might be coordinated profitably.
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From page 43...
... A variety of related scoring problems can beset such work, particularly with large-scare population-screening efforts. Microsatellite markers provide a rich source of genetic information and permit population assessments that were previously impossible, but the best laboratory control available must be used.
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From page 44...
... Although the pattern of rare types is intriguing, too much has been made ofthat information in view of available sample sizes; any inference attributed to the presence or absence of rare types in small samples is unreliable. The genetic resolution for measuring population divergence is in the high-frequency genetic markers, and the results in Tables 1-4 are insensitive to rare alleles or haplotypes.
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From page 45...
... USEFUL INFERENCE A statistically significant difference is not necessarily biologically meaningful. With large-enough sample sizes, any difference could be statistically significant.
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Key Terms

  • overlapping generations
  • genetic divergence
  • statistical tests
  • genetic variation
  • population genetic

  • nova scotia
  • allele frequencies
  • population size
  • population sizes
  • genetic markers

  • familial sampling
  • effective population
  • genetic analysis
  • commercial catches
  • previous work

  • age structure
  • rare types
  • electric charge
  • fish sampled
  • restricted set

  • discrete generations
  • effective size
  • single population
  • pairwise tests
  • random draw

  • natural selection
  • nonoverlapping generations
  • dna markers
  • intriguing question
  • square meters


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