Figure 3.

Clonal interference is substantial with even just a second adaptive trait. (A) The rate of adaptation of a focal trait as a function of the total number of traits undergoing adaptation, from Equation 2. The x-axis shows the total number of traits (including trait one) on a log scale. For k = 1, trait one evolves alone and there is no reduction, while for k = 2, trait one evolves at 62.2% of the rate that it would if it were not subject to clonal interference with a second trait. Steeply diminishing effects are seen with the addition of more traits. While the adaptation rate eventually asymptotes to zero for high k in Equation 2, note that this expression is only valid when $kU/s\ll 1.$ (B) Clonal interference between two traits is substantial and depends little on U and s, except in the top left corner where $kU/s\ll 1$ has broken down. Contour lines are labeled as the rate of adaptation in a focal trait relative to the rate that would be achieved in the absence of clonal interference with a second trait, matching the second point in (A). N = 10⁹ throughout and the points in (A) used s = 0.02, U = 10⁻⁵.