Reconstructed phylogenetic tree of 21 complete mtDNA genome sequences from haplogroups M12 and M7c'e. The six reported sequences were taken from the literature and were further labeled by the symbols MD , AC , QK1 , and QK2  followed by "#", the geographic locations, and the sample codes or the access numbers in GenBank. One sequence (Accession No. EU294322) submitted by "Family Tree DNA" was retrieved from GenBank. Haplogroup age estimates (±standard errors) are indicated at the branch roots in terms of the calibrated mutation rate with symbols as SP  and LE , respectively. Mutations are transitions at the respective nucleotide position unless otherwise specified. Letters following positions indicate transversions. Recurrent mutations are underlined. +: insertion; d: deletion; @: back-mutation. "R" specifies heteroplasmic status A/G and was also noted in italic. Amino acid replacements are specified by single-letter code; s, synonymous replacements; t, change in transfer RNA; r, change in ribosomal RNA gene.