Shifts in drift criterion result in equal but opposite changes in the drift rate for each choice (that is, a higher drift rate for old or new and a slower drift rate for the other) and thus drift criterion shifts have the same impact on distributions as a symmetrical change in drift rate itself.
Higher He flow rates reduces the average particle size by reducing the associated residence time in the aggregation zone due to a higher drift velocity of the Cu clusters within the growth region, similar to which occurs with Ar for high flow rates.
Interestingly, a higher drift rate may also explain the lower BOLD responses in hysteresis than in no hysteresis trials.
Hence the benefit of restricted pleiotropy we monitored is linked to a change of the maximum fitness reached (despite a higher drift load) and presumably not to a change of the rate of adaptation.
Increasing complexity allows the organisms to wonder in a larger phenotypic space and closer to the optimal combination of phenotypes, but it also leads to a higher drift load [ 12].
As such it appeared costly to have a high complexity due to a limited number of beneficial mutations [ 11, 13, 15, 21], a limited rate of adaptation [ 7, 11, 21, 22], or a higher drift load [ 12, 16, 20, 23- 25].
