Prehistoric humans left Africa for the first time about 2 million years ago. The research community has been aware of this for some time. Now, novel research reveals that hyenas apparently did the same thing.
'Our new study shows that prehistoric humans and hyenas left Africa at approximately the same time. And like humans, spotted hyenas have had extensive and complex migration between continents. We can observe repeated gene flow events between Africa and Eurasia', says Michael Westbury, corresponding author and postdoc at GLOBE Institute at the University of Copenhagen.
The researchers collaborated with researchers at the University of Potsdam and sequenced complete genomes from both modern spotted hyenas in Africa and subfossils of the extinct cave hyena from Europe and Asia.
Michael V. Westbury, Stefanie Hartmann, Axel Barlow, Michaela Preick, Bogdan Ridush, Doris Nagel, Thomas Rathgeber, Reinhard Ziegler, Gennady Baryshnikov, Guilian Sheng, Arne Ludwig, Ingrid Wiesel, Love Dalen, Faysal Bibi, Lars Werdelin, Rasmus Heller, Michael Hofreiter. Hyena paleogenomes reveal a complex evolutionary history of cross-continental gene flow between spotted and cave hyena. Science Advances, 2020; 6 (11): eaay0456 DOI: 10.1126/sciadv.aay0456
The genus Crocuta (African spotted and Eurasian cave hyenas) includes several closely related extinct and extant lineages. The relationships among these lineages, however, are contentious. Through the generation of population-level paleogenomes from late Pleistocene Eurasian cave hyena and genomes from modern African spotted hyena, we reveal the cross-continental evolutionary relationships between these enigmatic hyena lineages. We find a deep divergence (~2.5 Ma) between African and Eurasian Crocuta populations, suggesting that ancestral Crocuta left Africa around the same time as early Homo. Moreover, we find discordance between nuclear and mitochondrial phylogenies and evidence for bidirectional gene flow between African and Eurasian Crocuta after the lineages split, which may have complicated prior taxonomic classifications. Last, we find a number of introgressed loci that attained high frequencies within the recipient lineage, suggesting some level of adaptive advantage from admixture.