A lion from Constantine, Algeria was the type specimen for the specific name Felis leo used by Linnaeus in 1758. In the 19th and 20th centuries, several lion specimens from
Africa and Asia were described and proposed as subspecies:
In the following decades, there has been much debate among zoologists on the validity of proposed subspecies:
In 2017, lion populations in North, West and Central Africa and Asia were subsumed to P. l. leo by the Cat Classification Task Force of the IUCN Cat Specialist Group, based on results of genetic research on lion samples.
Since 2006, several phylogeographic studies were conducted to aid clarifying the taxonomic status of lion samples kept in museums and collected in the wild. Results indicate that lion populations in the northern part of Central Africa and Ethiopia are genetically close to populations in West and North Africa and Asia, whereas populations in the southern part of Central Africa are closer to populations in Southern and East Africa.
In a comprehensive study about the evolution of lions, 357 samples of 11 lion populations were examined, including some hybrid lions. The hybrids had descended from lions captured in Angola and Zimbabwe, and apparently West or Central Africa. Results indicated that four lions from Morocco did not exhibit any unique genetic characteristics and shared mitochondrial haplotypes H5 and H6 with lions from West Africa, and together with them were part of a major mtDNA grouping (lineage III) that also included Asiatic samples. This scenario was well in line with theories on lion evolution: lineage III developed in East Africa and traveled north and west in the first wave of lion expansions about 118,000 years ago. It apparently broke up into haplotypes H5 and H6 within Africa, and then into H7 and H8 in West Asia
Results of genetic analyses indicate that lions in West Africa and northern parts of Central Africa form distinct lion clades, which are more closely related to North African and Asiatic lions than to lions in Southern Africa and southern parts of East Africa. Lions from North Africa and India however, do form one single clade.Analysis of phylogenetic data of 194 lion samples from 22 different countries revealed that Central and West African lions form a phylogeographic group that probably diverged about 186,000–128,000 years ago from the melanochaita group in East and Southern Africa.
Several lions kept in Ethiopia's Addis Ababa Zoo were found to be genetically similar to wild lions from Cameroon and Chad.