Median joining haplotype network of mitochondrial cytochrome oxidase subunit I (<i>COI</i>) haplotypes of <i>Lucanus cervus</i> in Europe.

Partitions inside the circles represent the proportion of each region as given in Fig 1 within each haplotype. Circle size is proportionate with sample size. Haplotypes connected by a line differ in sequence by one mutational step and black dots represent unsampled or extinct haplotypes.