Illustration of time series alignment using DTW-S. (A) The x-axis shows human (dark yellow) and chimpanzee (yellow) age on a log2-scale, including conception time following . The y-axis shows expression of an example gene (VTA1) on a log2-scale. The triangles and the diamonds represent real expression values. The curves represent the spline curves. (B) The alignment results for the DTW-S procedure. The x-axis represents the rank of ages for interpolated points. The circles on the curves represent the interpolated expression values. The blue lines show alignment matches between the two interpolated time series calculated by the DTW-S algorithm. (C) The optimized time shift estimates for chimpanzee ages based on the expression pattern of VTA1, after aligning the chimpanzee time series to the human time series. (D) The y-axis shows the expression level after shifting chimpanzee expression time series by the magnitude of the time shifts estimated by the DTW-S algorithm (shown in C).