As our planet warms, as it has done for the last century or so, the change in temperature will have major effects on life. There are basically three possibilities for what might happen to a species: it can evolve to be better adapted to the new temperature, it can move closer to the poles so that it experiences temperatures closer to what it has experienced in the past, or it can go extinct. There have been a large number of studies of the second possibility. A study of the range limits of European butterflies found that, of 24 species that had changed their ranges in the last 100 years, 22 of them had moved further north and only two had moved further south (Parmesan et al. 1999). Assume that these 24 are a random sample of butterfly species with altered ranges. Test the hypothesis that the fraction of butterfly species moving north is different from the fraction moving south.