In population genetics, we talk about several types of genetic loads (also called just loads). I am asking for a exhaustive list and a short definition.

Here are for example some genetic loads that come to my mind..

  • Mutation load
  • Segregation load
  • Drift load
  • Lag load
  • 2
    $\begingroup$ Could add gender load - the cost of sexually antagonistic selection on traits with non-zero cross-sex genetic correlations (If SA selection affects shared genetic material then one/both sexes are constrained from reaching the optimal phenotype, this is the gender load). rspb.royalsocietypublishing.org/content/277/1686/1345.abstract $\endgroup$ – rg255 May 18 '14 at 20:38

The genetic load is a population construct, a way of quantifying the fitness reduction in a population due deviations from the optimal genotype.

One type of load comprises all the others, namely genetic load.

  • Genetic load is just the loss of mean fitness relative to the ideal fitness.

You forgot to include substitution load in your list, but otherwise I think you included all the main ones.

  • Substitution load is the total loss of mean fitness caused because favorable alleles substitute gradually by selection rather than instantaneously.

As for the ones you mentioned:

  • Mutational load is just the accumulation of deleterious alleles in a population.
  • Segregating load is the decrease in fitness in a population due to homozygotes being less fit.
  • Drift load is the fixation of deleterious alleles due to small population size. The smaller the population, the greater the risk of this happening.
  • Lag load is the loss of fitness due to a change in environment.

Another type, mentioned by rg255:

  • Gender load, which is the deviation from the optimum due to an allele drifting back and forth because the version that is optimal in one sex is not the one that is optimal in another.
|improve this answer|||||
  • $\begingroup$ Different load described here Lande 1976, Barton and Partridge 2000; Standing load: standing genetic variation in fitness, Migration load: new maladaptive variation due to gene flow, selection load: natural selection within a generation. Phenotypic load (Wallace, 1970) $\endgroup$ – M. Beausoleil Jul 20 '18 at 15:48

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.