Figure 1.

Three examples of gene genealogies for constant-sized populations of 5,000 chromosomes from which 30 chromosomes are sampled randomly. Associated allele length distributions are shown below for each example and are obtained by distributing stepwise mutations along the genealogy with an average frequency of 0.00056 per generation. The numbers at the bottom of each genealogy show the change in allele length from the ancestral chromosome to each of the sampled chromosomes.