  We study the adaptation dynamics of a maladapted asexual population on rugged
fitness landscapes with many local fitness peaks. The distribution of
beneficial fitness effects is assumed to belong to one of the three extreme
value domains, viz. Weibull, Gumbel and Fr{\'e}chet. We work in the strong
selection-weak mutation regime in which beneficial mutations fix sequentially,
and the population performs an uphill walk on the fitness landscape until a
local fitness peak is reached. A striking prediction of our analysis is that
the fitness difference between successive steps follows a pattern of
diminishing returns in the Weibull domain and accelerating returns in the
Fr{\'e}chet domain, as the initial fitness of the population is increased.
These trends are found to be robust with respect to fitness correlations. We
believe that this result can be exploited in experiments to determine the
extreme value domain of the distribution of beneficial fitness effects. Our
work here differs significantly from the previous ones that assume the
selection coefficient to be small. On taking large effect mutations into
account, we find that the length of the walk shows different qualitative trends
from those derived using small selection coefficient approximation.
