An ancient species of bison, which once roamed extensively for more than 100,000 years across Eurasia and North America, has only now been discovered by scientists — and they have ice age cave artists to thank for the find, reports Phys.org.
Cave paintings that date to more than 15,000 years ago seem to depict two different kinds of bison, one with long horns and large forequarters — familiar features of many modern bison — as well as one with odd-featured shorter horns and small humps. Researchers have long chalked up these differences to artistic imperfection, but new genetic analysis has proven that Ice Age cave artists knew exactly what they were doing.
Not only did genetic analysis reveal that an entirely new species of bison had once roamed across the world's northern latitudes, but it showed that the creature was the result of a hybridization event that occurred some 120,000 years ago between the extinct aurochs and the ice age steppe bison. Since hybridization rarely leads to speciation, this event represents an unexpected twist in the evolution of these magnificent beasts.
"Finding that a hybridization event led to a completely new species was a real surprise — as this isn't really meant to happen in mammals," explained study leader Alan Cooper. "The genetic signals from the ancient bison bones were very odd, but we weren't quite sure a species really existed - so we referred to it as the Higgs Bison."
"Higgs bison," the tentative new name for the mystery hybrid species, is a playful reference to the Higgs boson, an equally-elusive elementary particle in physics, the existence of which was also only just recently confirmed.
Interestingly, researchers also learned that the Higgs bison eventually became the ancestor of the modern European bison, or wisent, which means that its genetic heritage still survives into modern times.
"The dated bones revealed that our new species and the Steppe Bison swapped dominance in Europe several times, in concert with major environmental changes caused by climate change," explained lead author, Dr. Julien Soubrier. "When we asked, French cave researchers told us that there were indeed two distinct forms of bison art in Ice Age caves, and it turns out their ages match those of the different species. We'd never have guessed the cave artists had helpfully painted pictures of both species for us."
Paleontologists may want to begin paying closer attention to detail in ancient cave paintings. Who knows what other ancient species might be hiding in those depictions, first spied by human eyes thousands of years ago.