Few domesticated animals have as neat an origin story as the pet bunny.
As the story goes, around 600 A.D. Pope Gregory the Great issued an edict declaring that rabbit fetuses, called laurices, were not meat but fish. This was significant because it meant they could be eaten during Lent, a Christian period of repentance in preparation for the Easter holiday. As a result, French monks supposedly rushed to collect this new food source and breed them within the monastery walls, where they eventually grew into the loveable critters we know today.
It's a nice, neat tale of domestication. It also almost certainly never happened.
A new study, published in the journal Trends in Ecology and Evolution, takes a trip down the rabbit hole of recent rabbit evolution using a multi-faceted approach of genetic analysis, historical documents, archaeological remains and fossil evidence to tease out the real history of bunnies. The results suggest that this myth arose from a simple misinterpretation—and lends support to the idea that the story human interaction with wild beasts is inevitably a far more complex process than the legends say.
The study began when Greger Larson, an evolutionary biologist at Oxford University, was hoping to test a DNA modeling method his lab previously developed to map genetic history of modern domesticated and wild animals. Bunnies were an ideal test subject since their domestication seemed to have a definitive start: 600 A.D., when the Pope issued his edict.
"My first instinct was not to question that story," says Larson. But in an off-hand remark to his graduate student Evan Irving-Pease, who led the analyses, Larson requested he find a reference for the papal decree to pair with the genetic study. As Irving-Pease soon discovered, no such decree exists. So where did this domestication myth come from?
Irving-Pease traced the peculiar story to a 584 A.D. document from Gallo-Roman bishop and historian St. Gregory of Tours—not Pope Gregory the Great. The passage describes the actions of Roccolenus, a henchman from northern France, who planned to ransack the city of Tours. But before he could, the henchmen fell dead, incidentally after eating young rabbits during Lent. The passage was misinterpreted by scholars in the mid-1900s, and over time the apocryphal tale was born.
Next, the researchers turned to genetic analysis to fill out the picture. All modern pet bunnies come from wild rabbits of the species Oryctolagus cuniculus cuniculus, which likely roamed the South of France and northeast Spain for several million years. As documented in a 2014 study published in Science, during the last glacial maximum (roughly 18,000 years ago), advancing glaciers likely pushed the French bunnies back into Spain. Once the ice retreated, rabbits returned to France, with the marks of this population shift still discernible in their DNA. Our modern domesticated rabbits all evolved from the French populations, the DNA suggests.
To find out when exactly this happened, the Oxford team applied their DNA modelling method to parse through the genome of modern wild and tame French bunnies. What they found surprised them yet again: The analysis suggested a split occurred between 12,200 and 17,700 years ago, thousands of years before the supposed papal decree and well before records suggest intense bunny-human interaction.
To be clear, this doesn't suggest early Homo Sapiens had a fondness for the little fluffs. Instead, the split could reflect other factors, such as geographic separation, which limits mating and could have created several subgroups of bunnies, with some genetically closer than others. Later, one group of critters became domesticated.
Archaeological and historical records portray some of the many shifts in human-bunny relations over the years, Irving-Pease explains via email. "We hunted them during the Palaeolithic, housed them in Roman leporaria, kept them in Medieval pillow mounds and warrens, forced them to reproduce above ground in hutches, and only recently bred them for morphological novelties as pets," he writes. Together, these pieces show the winding history bunnies took from field to hutch.
But in a larger sense, Larson says, asking when exactly domestication begins is the wrong question. "We use this terminology that there is an implied understanding, but when you start to dig at it, when you start to reach for it, it just recedes from your fingertips," he says.
By seeking tidy origin stories for domestication, Larson argues, researchers overlook the complexities of the process. "A lot of our narratives work like this," he says, comparing the story of the Pope to the pervasive, but not entirely true, tale of Isaac Newton understanding gravity after an apple struck him on the head. In reality, he says, the process of scientific discovery is much more gradual—and so is the process of domestication.
Researchers often look for specific physical clues, like the floppy ears in dogs, which are visible traits associated with desirable features like a less aggressive personality. Although breeders don't select for floppy ears, this trait often crops up while trying to produce more friendly canines. But these physical or genetic markers alone don't tell the whole story.
For bunnies, telltale changes in coat color weren't documented until the 1500s, when domestication was in full swing. Skeletal changes, like differences in size, didn't come about until the 1700s, when pet breeding began. Each factor is a piece of the larger puzzle of humans interacting with wild beasts.
Melinda Zeder, senior scientist at Smithsonian's National Museum of Natural History and an adjunct professor of human ecology and Archaeobiology a the University of New Mexico, agrees with these conclusions. "The authors here are pointing out and trying to correct a really a longstanding fallacy—it's a little bit depressing that it still needs to be pointed out, but it does—that domestication is not a … point at which wild becomes domestic," she says. "It's a process."
Miguel Carneiro, evolutionary biologist at the CIBIO University of Porto who was part of the 2014 genetic analysis of rabbits, says that the study clears up historical misconceptions. "This is a timely paper that brings a healthy dose of skepticism regarding the timing of rabbit domestication and the associated cultural context," he writes in an email to Smithsonian.com.
Leif Andersson, a molecular geneticist at Uppsala University in Sweden and Texas A&M University agrees that the historical documentation has its merits. Andersson, who was also a senior author of the 2014 study, adds, "unfortunately, I think the authors of this paper make the same mistake as what they accuse others for in this manuscript … When we talk about the early domestications of for instance dog, pig and chicken it was certainly an ongoing process that happened over a long period of time," he writes. "But this does not mean that domestication always [has] to be a continuum that happened over a long period of time" in which wild and domestic groups continue to mix.
He points to the Syrian hamster, commonly known as the golden or dwarf hamster. Today’s dwarfs all supposedly originate from a single litter collected in 1930. But Larson and his team are currently investigating the case and believe the situation may be more complex. "Yes, there was removal of some hamster from a context," he says, "but they were from a farm in a burrow, so they were already close to human[s]." According to Larson, since their initial removal, "populations on these farms are [still] virtually identical to ones in the lab."
Understanding these human-animal interactions is increasingly important in today’s world, Zeder explains. "In an era when we think of things [that happened] 28 seconds ago as being out of date," she says, studying domestication "gives us a connection to a long heritage of human manipulation of the environment."
She adds, "the more that we understand that we're part of that long heritage, the more we will take responsibility for making sure it continues."