Boundaries of X-chromosome features showing correspondence with segmentation boundaries obtained from the first <i>six</i> steps (see Methods).

The boundaries labelled with ‘ ̂’ indicate cases when the JS divergence in a segment had more than one maximum of equivalent heights. The age of the strata on the X chromosome in the order of older to newer is S1, S2, S3, S4, S5, PAR. These strata are arranged linearly on the X chromosome in order from oldest to newest. Thus the boundary between PAR1 and S5 is most recent while the one between S1 and the rest of the chromosome is oldest; see Figure 1.