Figure 2.

Conditional independence structure of the data along a single chromosome. The chromosome is composed of a series of segments, each derived from one of the contributing populations. The zs indicate the population of origin of each marker along the chromosome; the sequence of zs forms a Markov chain with jump rate r. The genotype data (the Xs) are generated by drawing an allele at random from the appropriate population frequencies, given the zs. The genetic map distance between markers 1 and 2 is denoted d₁. The model for diploid unphased data is analogous.