Predators in general feed on N. pyrausta-infected O. nubilalis with no decrease in fitness.
Another robust inference is that the number of adaptive evolutionary paths is often limited to a relatively small fraction of the theoretical possibilities, owing largely to sign epistasis requiring evolutionary steps that would entail a decrease in fitness.
A 20% increase in fitness for individuals with the trait could balance an 85% decrease in fitness of homozygous HbSS individuals (Gelehrter et al. 1998).
The bottleneck effects often go with a decrease in fitness and in disease resistance [38] [40].
A second important process that can slow down adaptation or even result in a decrease in fitness is Muller's ratchet, which can be triggered by repeated bottlenecks [48] [51].
Dynamics of the different subpopulations in an antibiotic-free environment are the baseline that antibiotic treatments can alter by interfering with bacterial fitness (including colonisation and transmission), since resistance can be associated with a decrease in fitness [31].
Inbreeding generally causes a decrease in fitness [21] and is common in the herein studied metapopulation due to frequent bottlenecks during colonization of empty rock pools [33], [47], [48].
Hybrids may display intermediate parental morphology [3], [4], [5], [9] and fermentation properties [10], a switch from pathogen to mutualist [22], an increase in virulence [3], a decrease in fitness [13] and a new host range with respect to their parents [3].
Inbreeding depression, or the decrease in fitness due to mating between relatives, is an important ecological and evolutionary phenomenon, which has been widely studied from multiple perspectives, such as population genetics, mating system evolution or conservation biology, and for a broad range or organisms [1], [2].
<F̅> and the lowest fitness over individuals F̅min, after a sufficiently large number of generations, are plotted against σ in Fig. 2. The abrupt decrease in fitness suggests threshold noise σc, below which low-fitness mutants always remain in the distribution.
What might explain the early decrease in fitness of the E2 population?
