Complex phylogeographic history of central African forest elephants and its implications for taxonomy

Abstract

BackgroundPrevious phylogenetic analyses of African elephants have included limited numbers of forest elephant samples. A large-scale assessment of mitochondrial DNA diversity in forest elephant populations here reveals a more complex evolutionary history in African elephants as a whole than two-taxon models assume.ResultsWe analysed hypervariable region 1 of the mitochondrial control region for 71 new central African forest elephants and the mitochondrial cytochrome b gene from 28 new samples and compare these sequences to other African elephant data. We find that central African forest elephant populations fall into at least two lineages and that west African elephants (both forest and savannah) share their mitochondrial history almost exclusively with central African forest elephants. We also find that central African forest populations show lower genetic diversity than those in savannahs, and infer a recent population expansion.ConclusionOur data do not support the separation of African elephants into two evolutionary lineages. The demographic history of African elephants seems more complex, with a combination of multiple refugial mitochondrial lineages and recurrent hybridization among them rendering a simple forest/savannah elephant split inapplicable to modern African elephant populations.

The cryptic genetic structure of the North American captive gorilla population

“…Our results are not unlike those of a recent study of North American captive savannah elephants that found no genetic structure in the founder population (Lei et al 2008) despite individuals having origins ranging from east, to central, to southern Africa (Olson 2003). Despite morphological Grubb et al 2000) and genetic (Roca et al 2001) differences between savannah and forest elephants being clear, introgression is evident in the wild populations (Roca et al 2004;Debruyne 2005;Johnson et al 2007), and admixture is shown in the captive population (see Debruyne 2005;Lei et al 2008). Analogous to the cryptic genetic variation and gene flow in elephants, our results show that there was genetic exchange between the two gorilla genetic clusters (as evidenced by the existence of admixed individuals in the wild-born founders) before they were moved from the wild in Africa to North America.…”

Forensic species identification of elephant (Elephantidae) and giraffe (Giraffidae) tail hair using light microscopy

“…Background data on these vouchered samples were previously published [1]. While the forest elephant is recognized as a full species (Loxodonta cyclotis) by some researchers [20], here we follow CITES taxonomy and other researchers who treat Loxodonta from Africa as a single species (Loxodonta africana) [21].…”

Application of PCR Technologies to Humans, Animals, Plants and Pathogens from Central Africa

“…As described above, problems related to sampling were well circumvented with animals. Indeed, by using shed hair or feces, which are non invasive methods of sampling, phylogenetic analyses have allowed a better understanding of the evolutionary history of gorillas [46] mandrills [47] or elephants [48]. Equally, a number of simian viruses have been characterized in fecal samples, which is more convenient, especially in case of wild-living primates.…”

“…Despite their morphology typical from forest elephants, a genetic study based on mtDNA [48] shows that Central African elephants are sharing their history with both forest and savannah elephants from Western Africa. It also gives evidence that Central African forest populations show lower genetic diversity than those in savannahs, and infers a recent population expansion.…”