Emilia Martins' 1998 study compared the head-bob displays from the source population on Cuba with these animals on Isla Magueyes.[1] The durations and pauses were longer by as much as 350% in the feral population.[30] In comparison, the blue iguana of Grand Cayman's head-bob displays differed from those of the animals on Cuba by only about 20%.[30] The rapid change in display structure between the colony of animals on Isla Magueyes and those on Cuba illustrated the potential of small founding population size as a catalyst to evolution with regard to communication or display.[30] In this case the difference was by only six generations at most.[30]