Loading ...
Sorry, an error occurred while loading the content.
 

[evol-psych] Inbreeding depression in the wild

Expand Messages
  • Ian Pitchford
    From the current issue of Heredity Crnokrak, P., & Roff, D.A. (1999). Inbreeding depression in the wild. Heredity, 83, 260-270. Despite its practical
    Message 1 of 1 , Oct 31, 1999
      From the current issue of Heredity

      Crnokrak, P., & Roff, D.A. (1999). Inbreeding depression in the wild. Heredity,
      83, 260-270.

      Despite its practical application in conservation biology and evolutionary
      theory, the cost of inbreeding in natural populations of plants and animals
      remains to a large degree unknown. In this review we have gathered estimates of
      inbreeding depression (delta) from the literature for wild species monitored in
      the field. We have also corrected estimates of delta; by dividing by F
      (coefficient of inbreeding), to take into account the influence that the
      variation in F will have on delta. Our data set includes seven bird species,
      nine mammal species, four species of poikilotherms (snakes, fish and snails)
      and 15 plant species. In total we obtained 169 estimates of inbreeding
      depression for 137 traits; 81 of those estimates included estimates of F. We
      compared our mammalian data (limited to those traits related to juvenile
      mortality) to the estimates for captive zoo species published by Ralls et al.
      (1988) to determine if, as predicted from the literature, natural estimates of
      inbreeding depression are higher than captive estimates. The mean delta ± SE
      (significantly different from zero and not corrected for F ) for homeotherms
      was 0.509 ± 0.081; for poikilotherms, 0.201 ± 0.039; and for plants, 0.331 ±
      0.038. Levels of inbreeding depression this high in magnitude will be
      biologically important under natural conditions. When we limited our data set
      to mortality traits for mammals and corrected for F=0.25 (as is the case for
      the Ralls et al. data set), we found a significant difference between the two
      data sets; wild estimates had a substantially higher mean cost of inbreeding at
      F = 0.25: 2.155 (captive species: 0.314). Of the 169 estimates of delta, 90
      were significantly different from zero, indicating that inbred wild species
      measured under natural conditions frequently exhibit moderate to high levels of
      inbreeding depression in fitness traits.

      Ian Pitchford <Ian.Pitchford@...>
      Centre for Psychotherapeutic Studies
      School of Health and Related Research
      University of Sheffield, S10 2TA, UK
      http://www.human-nature.com/
    Your message has been successfully submitted and would be delivered to recipients shortly.