Conservation Genetics

, Volume 12, Issue 2, pp 343–353 | Cite as

The consequences on fitness of equating family contributions: inferences from a drosophila experiment

  • Enrique Sánchez-Molano
  • Aurora García-DoradoEmail author
Research Article


Here we present results of a Drosophila long term experiment where we study the fitness consequences of equating the number of breeding offspring contributed per family (EC) compared to a random contribution (RC) protocol. The EC strategy slows inbreeding and drift. However, it also prevents natural selection on fecundity and limits selection on viability to that occurring within families, and this includes purge against unconditionally deleterious alleles as well as adaptation to captive conditions. We used populations maintained with 5 or 25 single mated pairs, monitored inbreeding and selection intensity, and assayed competitive and non competitive fitness, as well as fecundity and viability components, in lines maintained with or without EC. In the small lines, EC showed modest advantage for viability during the whole experiment and for fitness up to generation 15 while, in the large lines, fitness increased steadily under both strategies, and EC led in the medium term to a slight fitness disadvantage. On the light of recent theory, these results can be explained as the joint consequence of new and standing deleterious mutations undergoing drift, inbreeding and selection and of adaptation to captive conditions.


Inbreeding depression Purge Conservation Adaptation to captive conditions Fitness components Population number 



We are grateful to Carlos López-Fanjul for useful discussion and to Mauro Santos for providing the original Drosophila sample. This work was supported by grants CGL2008-02343/BOS from the Ministerio de Ciencia e Innovación and UCM-BSCH GR58/08-910433 from the Universidad Complutense.


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Copyright information

© Springer Science+Business Media B.V. 2010

Authors and Affiliations

  • Enrique Sánchez-Molano
    • 1
  • Aurora García-Dorado
    • 1
    Email author
  1. 1.Departamento de Genética, Facultad de BiologíaUniversidad Complutense de MadridMadridSpain

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