Population expansion signatures in mitochondrial ND4 sequence data. Top panel: Mismatch distribution of observed frequencies of pairwise differences among ND4 sequences and expected frequencies under the neutral model of evolution given the null hypothesis of 1) no population change and 2) population expansion. Bottom panel: Site-frequency spectrum indicating excess of singleton mutations in ND4 sequence. Spectrum compares observed frequencies of segregating sites to expected distribution under the null hypothesis of no population change.