To sweat herself younger, she stretches, lifts weights, runs races, and signs up for not one but two classes featuring the repeated spurts of all-out exertion thought to optimize fitness.
Three of these studies, Bedau and Packard [19], Earl and Deem [16] and Clune et al. [20] specifically address the problem of whether an intermediate mutation rate can optimize fitness.
These abiotic factors may induce morphological adjustments in broadly distributed species to optimize fitness under suboptimal conditions.
Moreover, different traits may optimize fitness when the population is at high density near K, the carrying capacity.
Spreading reproduction across time or space can optimize fitness by minimizing the risks for offspring survival in varying and unpredictable environments.
Mutation and natural selection turn the knobs to adjust behavior so as to optimize fitness in the environment in which the animal finds itself.
For many animals, and fish in particular, it appears that species have evolved a suite of linked life-history, metabolic and behavioural traits integrated to optimize fitness within their native environment (Biro and Stamps 2008, 2010; Careau et al. 2010).
Thus, the placement of these 'mitochondrially-sensitive (mito-sensitive )' nuclear genes on the autosomes [ 18], and off the X, would drive compensatory mito-nuclear trajectories in a direction that optimizes fitness in both sexes.
Since environmental conditions and resource availability were constant for all aspects of our study, we can probably rule out environmental variation as a factor (trade-offs allow a female to optimize fitness by maximizing resource potential [ 72]; when resources are in abundance, a trade-off may not exist (see [ 71, 73]).
