The graph in Figure. shows FST, a measure of genetic differentiation between populations a...

The graph in Figure. shows FST, a measure of genetic differentiation between populations as a function of geographic distance. The data are from human populations in Europe. Genetic differentiation has been calculated based on loci on the autosomes (inherited from both parents), the mitochondrial chromosome (inherited only from the mother), and the Y chromosome (inherited only from the father). Note that the patterns are different for the three different kinds of loci. Keep in mind that migration tends to homogenize allele frequencies across populations. Develop a hypothesis to explain why allele frequencies are more homogenized across populations for autosomal and mitochondrial loci than for Y-chromosome loci. Then go to the library and look up the following paper, to see if your hypothesis is similar to the one favored by the biologists who prepared the graph:

Seielstad, M. T., E. Minch, and L. L. Cavalli-Sforza. 1998. Genetic evidence for. .. in humans. Nature Genetics 20: 278–280. [Part of title deleted to encourage readers to develop their own hypotheses.]

Figure Genetic distance between human populations as a function of geographic distance Colors indicate that genetic distance (FST) has been calculated based on three different kinds of loci. From Seielstad et al. (1998).