One of the most iconic animals in Africa has a secret. A genetic analysis suggests that the giraffe is not one species, but 4 separate ones — a finding that could alter how conservationists protect these animals. Researchers previously split giraffes into several subspecies on the basis of their coat patterns and where they lived. Closer inspection of their genes, however, reveals that giraffes should actually be divided into four distinct lineages that don’t interbreed in the wild, researchers report on 8 September in Current Biology1. Previous genetic studies2 have suggested that there were discrete giraffe populations that rarely intermingled, but this is the first to detect species-level differences, says Axel Janke, a geneticist at Goethe University in Frankfurt, Germany, and the study’s senior author.
“It was an amazing finding,” he says. He notes that giraffes are highly mobile, wide-ranging animals that would have many chances to interbreed in the wild if they were so inclined: “The million-dollar question is what kept them apart in the past.” Janke speculates that rivers or other physical barriers kept populations separate long enough for new species to arise.