The debate over how many giraffe species there are continues, despite the generation of additional giraffe genomes, The Scientist reports.
Researchers led by Axel Janke from the Senckenberg Biodiversity and Climate Research Center in Germany conducted whole-genome analyses of about 50 giraffe genomes, representing all or suspected subspecies in a bid to end the discussion. According to The Scientist, Janke and his colleagues previously argued there were four giraffe species, but others have maintained there are as few as three or as many as eight.
Janke and his colleagues now report in Current Biology that their population structure and phylogenomic analyses still point to four giraffe lineages, which they found diverged between 230,000 and 370,000 years ago and have had limited admixture and gene flow. That, they argue, suggests the lineages should be considered separate species.
But as The Scientist reports, not everyone is convinced. The Sorbonne's Alexandre Hassanin tells it that had Janke and his colleagues included additional samples, they might have seen evidence of admixture between Giraffa reticulata and G. camelopardalis, suggesting there are only three giraffe species. Meanwhile, Penn State University's Douglas Cavener tells it that Janke and his colleagues' samples could have included family members and thus underestimate the diversity of and the number of species of giraffes.