Guinea pigs are quite the mystery, considering how common they are as research animals and how popular they are as pets for children. That in itself is a mystery – in the home, guinea pigs don’t seem to do much other than eat and relieve themselves, and many don’t like to be petted, let alone picked up. You can try to train them to subservience to caresses by conditioning, i.e., approaching them slowly and gradually, and giving them treats. It doesn’t always work.
In other words, guinea pigs don’t like you by default and have to be won over – which people have been working on for thousands of years, it turns out. Having gained its tolerance, if not its affection, your reward will likely be that it will amiably defecate on your lap. Truth is, they should be grateful you’re not eating them, which seems to have been their main role in prehistory going back at least 10,000 years.
And now, an intrepid international team has delved into the knotty conundrum of guinea pig domestication by genetic analysis, with somewhat surprising results, reported recently in Scientific Advances.
The team analyzed the mitochondrial genomes of 46 guinea pigs from archaeological sites in Peru, Bolivia, Colombia, the Caribbean, Belgium and the United States, seeking insight on the animals’ evolution and dispersal. At least some insight was gained.
However, some insights were not gained. One wonders how many species of guinea pig (Cavia) there are exactly. “There is quite some debate as to exactly how many species of Cavia there are – somewhere between 3 and 11,” Lisa Matisoo-Smith of the University of Otago, New Zealand, tells Haaretz.
The point of the study was more to elucidate where the guinea pigs found around the world came from. And there, progress was made.
The squeal deal
- How interbreeding with Denisovans affected human health
- 45,000-year-old arrows in Sri Lanka show how we conquered the world
- Uncovering the secrets of the Indus Valley civilization and its undeciphered script
These deceptively cute rodents are not ungulates and they’re not from Guinea. The family is endemic to South America. And the first insight is that the animal we all know and love, though it regards us askance, is of southern Peruvian origin, apparently. Or possibly Bolivian.
“It is also possible that guinea pigs came to Europe from northern Chile, although samples from this area have not yet been analyzed,” the team qualifies.
Let’s say Peru. In any case, all pet guinea pigs come from a single distinguished Andean lineage, Cavia porcellus, and it seems all lab guinea pigs too, Matisoo-Smith says. (Long-haired guinea pigs and so on aren’t different species, they’re variants.)
Cavia porcellus descended from the wild species Cavia tschudii, which was likely domesticated in Peru, she elaborates.
“We also demonstrate that Peru was the probable source of the earliest known guinea pigs transported, as part of the exotic pet trade, to both Europe and the southeastern United States,” Matisoo-Smith adds.
This happened at very different times. “The samples that we have from Belgium – reported in the paper – are the oldest known guinea pig remains in Europe,” she says. Guinea pig remains found at Mons, Belgium, date to about 1550-1640. The team also dated guinea pig remains found at Hill Hall, a mansion in southern England, to 1574–1575. “It looks like early Spanish explorers brought them back to Europe,” Matisoo-Smith suggests.
Apparently, the exotic rodent only reached the United States hundreds of years later. The earliest known specimen was retrieved – hate to say this – from a toilet in Charleston, South Carolina, and was dated to the year 1820. It also hailed from Peru. The remains of the Charleston ex-pet were discovered together with those of an Amazonian parrot, suggesting to the researchers that the two animals had been acquired as South American “curiosities.” One can only hope they were dead before being discarded.
However, the evidence suggests to the team that guinea pigs had also been domesticated in the eastern Colombian highlands thousands of years ago. One wonders what became of those.
“Of the Colombian samples that we sequenced, the oldest samples may have been wild varieties,” Matisoo-Smith elaborates. But there is a significant difference between these oldest remains and those of the Colombian samples that are merely several hundreds of years old, which suggests the latter result from independent domestication at some point in the last few thousand years.
“We think that the species we sequenced from the ancient highland Colombian sites is Cavia anolaimae and a domesticated form of this species,” she says. “They didn’t become extinct, but it appears that they are not domesticated anywhere else and were not translocated to the Caribbean” – which the Peruvian animal was, about 1,400 years ago.
‘Little piggy from the sea’
The team also discovered that guinea pigs began leaving the shores of their homeland in pre-Colombian times, about 1,400 years ago, reaching the Caribbean Antilles. These seafaring guinea pigs were from the Peruvian-derived population. There is no evidence that the Colombian species of the animal left its homeland.
Also, there is no archaeological evidence for guinea pigs along coastal Central America, coastal Colombia, or elsewhere in northern coastal South America, the team explains. The rodents in the Caribbean hailed from Peru. In fact, they constitute the earliest empirical evidence of interactions between the Caribbean Antilles and this region of western South America, the team writes.
Finally, the team identified a modern reintroduction of guinea pigs to Puerto Rico, where they are generally eaten, not kept as pets.
Matisoo-Smith elaborates that the debate over the Colombian species continues: whether they are a distinct species, or possibly a sub-species of either Cavia porcellus or Cavia aperea, the Brazilian guinea pig (which also still exists). “But we see that there is as much difference (1,400+ DNA differences in the mitochondrial genome) between the ancient Colombian samples that we sequenced and the ancient Peruvian samples that we sequenced, to suggest that they are a different species to C. Porcellus,” she sums up.
So there we have it. People beyond South America are seemingly meeting the Peruvian guinea pig, which is apparently distinct from the Colombian and Brazilian guinea pigs. Which leaves us, at this point, to wonder where that strange name came from.
We don’t know anymore. Some think the “guinea” part of their name derives from sailors of yore selling the hapless rodents for a guinea, and that the “pig” bit stems from their squealing when distressed, often by your unwelcome attentions.
In Hebrew, oddly, guinea pigs have two names – “sharkan,” meaning “whistler,” or “hazeer yam,” which means “sea pig.” (“Sharkan” is a bit of a misnomer: they’re not whistling, they’re shrieking. But nu.)
Consultation with linguistics expert and Haaretz columnist Elon Gilad elucidated that “hazeer yam” originated in the German name Meerschweinchen – “little piggy from the sea.” So in Israel, the animals are basically known as screaming sea pigs. They’re still quite popular though.
It bears adding that they’re not kosher. The Torah specifies that no rodent is kosher, so they can’t be sold here as lunch meat.
Cavia, Gilad adds, is their Latin name based on the Portuguese rendition of the original indigenous South American name for the animal in Old Tupi, a language of Brazil, not Peru. We can assume they ate guinea pig, rather than capturing and keeping it for its charms.