THE EFFECT OF POPULATION-SIZE ON EFFECTIVE POPULATION-SIZE - AN EMPIRICAL-STUDY IN THE RED FLOUR BEETLE TRIBOLIUM-CASTANEUM

Despite the increasing number of studies on the magnitude of N-e/N rat ios, much remains unknown about the effects of demographic and environ mental variables on N-e/N. We determined N-e/N for seven population si ze treatments, ranging from N = 2 to N = 960, in the red flour beetle Tribolium castaneum. N-e/N decreased with increasing N, as evidenced b y a significant negative relationship between log N and N-e/N. Our res ults are consistent with other published data on the relationship betw een N-e/N and N. Effective population sizes in large populations may b e much smaller than previously recognized. These results have importan t implications for conservation and evolutionary biology.