Woods expects to start fitness training again by the end of the week but will not be able to start hitting balls again until he knows how his leg responds.
Nevertheless, there are several hints of an underlying relationship between starting fitness and subsequent mutation rate.
Competitive exclusion and displacement when two viral populations with nearly equal starting fitness compete has been observed [ 4].
R and F showed similar absolute fitness values, which rules out possible differences in evolvability due to differences in starting fitness values (relative fitness values are reported hereafter, but similar results were obtained with absolute fitness values).
Taken at face value, the results of this study suggest that, on average, the mutational process does not vary in a consistent way with starting fitness.
As starting tree, the same WNV original tree was used and its fitness at r = 8 was considered as starting fitness for the computation of relative fitness improvement (final tree fitness/original tree fitness).
These nonsignificant trends highlight two issues concerning the power of an experiment to detect a significant association between starting fitness (or any generic property of the organism) and subsequent MA.
We can imagine several possible, nonexclusive reasons for the discrepancy between the absence of a significant relationship between starting fitness and mutational properties in this experiment and the results of the experiments mentioned above.
The relevant independent variables are Gmax (generations of MA, 150 for 2° MA lines, and 0 for the 1° control); Treatment (a categorical variable equivalent to Gmax, 1° control vs. 2° MA), starting Fitness (high or low fitness of the 1° MA lines), Line (1° MA line, nested within Fitness), Subline (2° MA subline, nested within Line), and Replicate (nested within Subline).
However, we have also compared the two selection scenarios when the starting fitnesses of all-or-nothing and hill-climb are the same independent of the starting number of necessary mutations, and discuss the subtle tradeoff between the fitness advantage of, and clonal-interference among, intermediate mutants (figs. S7 and S8) (6, 19).
