The origin, current diversity and future conservation of the modern lion (Panthera leo)

Abstract

Understanding the phylogeographic processes affecting endangered species is crucial both to interpreting their evolutionary history and to the establishment of conservation strategies. Lions provide a key opportunity to explore such processes; however, a lack of genetic diversity and shortage of suitable samples has until now hindered such investigation. We used mitochondrial control region DNA (mtDNA) sequences to investigate the phylogeographic history of modern lions, using samples from across their entire range. We find the sub-Saharan African lions are basal among modern lions, supporting a single African origin model of modern lion evolution, equivalent to the 'recent African origin' model of modern human evolution. We also find the greatest variety of mtDNA haplotypes in the centre of Africa, which may be due to the distribution of physical barriers and continental-scale habitat changes caused by Pleistocene glacial oscillations. Our results suggest that the modern lion may currently consist of three geographic populations on the basis of their recent evolutionary history: North African-Asian, southern African and middle African. Future conservation strategies should take these evolutionary subdivisions into consideration.

Figure 1

Map showing approximate sampling sites with mtDNA haplotypes: numbers in circles correspond to different haplotypes. The numbers superscripted beside the circles correspond with the ID numbers in table 1. If more than one sample originates from the same country (or region) and the exact sampling location is not known for every animal, a dashed circle and dashed line were used. The Great Rift Valley is shown as thick dark lines.

Figure 2

Median-joining network for lion mtDNA haplotypes. Different numbers represent different haplotypes, corresponding to those in figure 1 and table 1. The area of the circle is proportional to the haplotype frequency, and the length of connecting lines to the distance between haplotypes, defined as the number of substitutions estimated by Network v. 4.1.0.3 (Bandelt et al. 1999). A place where lines meet without a circle indicates the possible ancestral state. Maximum parsimony bootstrap support for groupings is in bold.

Figure 3

Estimated shift of the natural distribution range of the modern lion in the last ca 20 000 years: (a) at the last glacial maximum ca 20 000 years ago, (b) during the Early Holocene wetter period ca 10 000–4000 years ago and (c) present.