  We study the evolutionary Prisoner's Dilemma game on scale-free networks for
different initial distributions. We consider three types of initial
distributions for cooperators and defectors: initially random distribution with
different frequencies of defectors; intentional organization with defectors
initially occupying the most connected nodes with different fractions of
defectors; intentional assignment for cooperators occupying the most connected
nodes with different proportions of defectors at the beginning. It is shown
that initial configurations for cooperators and defectors can influence the
stationary level of cooperation and the evolution speed of cooperation.
Organizations with the vertices with highest connectivity representing
individuals cooperators could exhibit the most robust cooperation and drive
evolutionary process to converge fastest to the high steady cooperation in the
three situations of initial distributions. Otherwise, we determine the critical
initial frequencies of defectors above which the extinction of cooperators
occurs for the respective initial distributions, and find that the presence of
network loops and clusters for cooperators can favor the emergence of
cooperation.
