Figure 15: Variation in the ratio of lengths of human and chicken DNA in aligned segments.

a, Dot plot comparing orthologous regions of human and chicken, showing variable slope. b, Variation in log-transformed ratio of lengths of aligned segments, comparing human–chicken (green, all; non-repetitive, red) and human–mouse (black). c, Scatter plot of the log-transformed ratio of lengths of orthologous human and chicken segments versus ratio of repeat-masked sequence in the two species. d, Scatter plot of the log-transformed ratio of lengths versus ratio of G+C contents after removal of masked bases. Lowess smooths (locally weighted scatterplot smoothing) are superimposed (red curves; smoothing parameter 0.5). See Methods for details.