2025/04/21 by Bridget O. Ogolowa, Alan Brelsford, Jon Fjeldså +10 · 1 voice
Biochemistry, Genetics and Molecular Biology · Earth and Planetary Sciences · Environmental Science · #Ecology and Vegetation Dynamics Studies #Evolution and Paleontology Studies #Genetic diversity and population structure
paper · pdf · doi:10.1111/mec.17770
openalex publication_date 2025/04/21 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/29
Diversification mechanisms in Sub-Saharan Africa have long attracted research interest, with varying support for either allopatric or parapatric models of speciation. However, studies have seldom been performed across the entire continent, a scale which could elucidate the relative importance of allopatric and parapatric models of divergence. To shed light on continental-scale patterns of African biogeography and diversification, we investigated the historical demography of a bird with a continent-wide distribution in Sub-Saharan Africa, the Yellow-Rumped Tinkerbird, Pogoniulus bilineatus. We sampled populations from across the continent and, using genomic data, assessed genetic diversity, structure, and differentiation, reconstructed the phylogeny, and performed alternative demographic model selection between neighbouring clade pairs. We uncovered substantial genetic structure and differentiation patterns which corroborated the phylogenetic topology. Structure was chiefly influenced by the arid corridor, a postulated biogeographical barrier in Sub-Saharan Africa. Moreover, peak genetic diversities coincided with postulated refugial areas while demographic reconstructions between genetic lineages supported allopatric models consistent with the Pleistocene Forest Refuge hypothesis. However, within lineages, divergence with gene flow was supported. Continent-wide patterns of diversification involve an integration of both allopatric and parapatric mechanisms, with a role for both periods of divergence in isolation and across ecological gradients. Furthermore, our study emphasises the importance of the arid corridor as a primary biogeographical feature across which diversification occurs, yet one that has hitherto received scant attention regarding its importance in avian diversification in Sub-Saharan Africa.