Schematic representation of elephantid mtDNA phylogenies under introgression scenarios. (a,b) Hypothetical mammoth (b) (this study) and observed African elephant (a)  cladograms, with male body size comparisons and predominant geographic ranges of the species indicated. Solid lines represent observed data; dashed lines represent predicted but presently unobserved lineages under an M. primigenius-M. columbi introgression hypothesis.
Enk et al. Genome Biology 2011 12:R51 doi:10.1186/gb-2011-12-5-r51