Computer simulations of the genetic load
Finally, we performed computer simulations examining the impact of
genomics-informed captive breeding on the neutral nucleotide diversity,
genetic load, realised load, and fitness of individuals. The ”Random
mating” and “Minimise relatedness” regimes showed a steady increase in
genetic (Fig. 5A) and realised (Fig. 5B) load over generations. Both
regimes also suffered from a large decline in fitness due to a mutation
meltdown (Fig. 5C). In contrast, both the genetic load and realised load
were reduced in “Minimise load” and “Minimise load and relatedness”
regimes (Fig. 5A,B). Therefore, genomics-informed captive breeding can
effectively purge deleterious mutations and reduce their homozygosity,
independently of consideration of relatedness. Consequently, mean
fitness remained high in these regimes, increasing during the first ten
generations (Fig. 5C). However, populations lost neutral genetic
diversity at a relatively fast rate in the “Minimise load” regime
(Fig. 5D). Such loss in diversity was not observed in the “Minimise
load and relatedness” regime, and after ∼10 generations, this regime
maintained more diversity than the “Random mating” regime (Fig. 5D).