A comparison of management strategies for conservation with regard to population fitness

Computer simulations have been carried out tocompare, under realistic genetic models, twomethods proposed in the literature to retaingenetic diversity in conservation programmes.In a two-step method, contributions of parentsare set up to produce minimum coancestry(kinship) among the offspring, and this isindependent of the mating system subsequentlyapplied. In a single-step method,contributions and matings are decidedsimultaneously in order to minimise coancestry.The comparison is made in terms of maintainedgenetic diversity and in terms of populationfitness. We conclude that the two methodsmaintain approximately the same geneticdiversity but the latter induces higher levelsof inbreeding, reducing the fitness of thepopulation. Avoidance of close relatives'matings improves this latter method, but thefitness levels do not reach those of thetwo-step scheme. We also investigate theperformances of different mating strategies incombination with minimum coancestry (two-stepmethod), concluding that these mating systemsdo not substantially affect the effectivenessof the management. Finally, we illustrate howminimum group coancestry can be restrictedto a minimum loss of fitness, if a measure ofthis is available for the individuals.