Journal of Genetics (2019) 98:83 © Indian Academy of Sciences https://doi.org/10.1007/s12041-019-1125-y PERSPECTIVES African elephant genetics: enigmas and anomalies† ALFRED L. ROCA1,2∗ 1Department of Animal Sciences, and 2Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA *E-mail:
[email protected]. Received 5 November 2018; revised 28 March 2019; accepted 27 May 2019 Keywords. elephants; mito-nuclear; subspecies; effective population size; glacial refugia. During the last two decades, our understanding of the Introduction genetics of African elephant populations has greatly increas- ed. Strong evidence, both morphological and genetic, sup- Morphological analyses of skull dimensions of African ele- ports recognition of two African elephant species: the phants from widespread locations in Africa have revealed savanna elephant (Loxodonta africana) and the forest ele- complete separation morphologically between forest and phant (L. cyclotis). Among elephantids, phylogeographic savanna elephants, with a few intermediaries primarily patterns for mitochondrial DNA are highly incongruent with in habitat transition zones (Groves and Grubb 2000a, b; those detected using nuclear DNA markers, and this incon- Grubb et al. 2000). Various nuclear genetic studies have gruence is almost certainly due to strongly male-biased gene also reported that forest and savanna elephants are genet- flow in elephants. As our understanding of elephant popula- ically distinct and deeply divergent (Roca et al. 2001; tion genetics has grown, a number of observations may be Comstock et al. 2002; Rohland et al. 2010; Palkopoulou considered enigmatic or anomalous. Here, several of these et al. 2018), with a limited degree of ongoing hybridization are discussed.