The evolution and conservation of the African forest elephant

The development of molecular genetic tools to genotype animals from traces has revolutionized the study of elusive or dangerous species. In this dissertation, I used DNA extracted from dung collected in wild populations to investigate the evolution and population genetics of African forest elephants.; Previously, the evolutionary history of Loxodonta africana was known only from fossil evidence and a single genetic study of east and central African savanna elephants. I combined my genetic study of the relationship between the forest and savanna elephants of west and central Africa with mitochondrial DNA sequences from eastern and southern African elephants, to perform the most comprehensive study of African elephant phylogeography and evolution to date. The results indicate that L. africana arose in the forests of central Africa between 4 and 5 mya. Climate change during the mid-Pliocene resulted in southern populations becoming adapted to a cooler, dryer and more open environment, giving rise to elephants of the savanna form. During a later episode of cooler, dryer climate, elephants again moved from the forests into the savannas, as well as into the forests of west Africa. As a result, there are two deeply divergent mitochondrial lineages present in many savanna populations and the forests of west Africa. This complex history, which was influenced by global climate change, has resulted in three recognizable subspecies or semispecies: the central African forest elephant, L. a. cyclotis; the savanna elephant of eastern, southern, and central Africa, L. a. africana; and the newly recognized west African elephant, L. a. occidentalis.; My methods also allowed me to do an in-depth study of an important forest elephant population. Since effective management of wildlife populations requires census data, I performed a genetic census using nuclear microsatellite DNA extracted from dung. I combined the population size estimate with field observations to estimate the age structure of the population. The resulting estimates of population size, sex ratio, age structure and level of genetic diversity provide essential, but previously unavailable, data that the Wildlife Division of the Forestry Department in Ghana can use to manage this population in one of their premier national parks.