Cockfighting, Academic Style
Want to see a really good fight? Get a few anthropologists together in a room and ask them when chickens first arrived in the New World. Then back away and start placing your bets.
How chickens came to the Americas is one of the great unresolved anthropological debates. On the one hand you have those who believe chickens arrived in the New World with the Spaniards and/or Portuguese. On the other you have those who contend that chickens arrived far earlier and from the other direction, via the Polynesians. A few outliers claim ancient Egyptian seafarers brought them, but most of those types also believe in the Loch Ness Monster.
For what it’s worth, I think the preponderance of evidence is on the Polynesian side. True, early explorers like Vicente Pinzón and Pedro Cabral had chickens with them when they made landfall in Brazil. However when Pizarro arrived on the other side of the Continent some 30 years later to initiate his conquest of the Incas, he found an extremely well-established chicken culture — more well-established than one would expect if chickens had only been introduced 30 years before, and then on the other side of South America. Just how well-established was it? Well, not only did Pizarro note quite a few chicken-inspired place names, people names and artworks, he also noticed that the words for chicken and egg weren’t even remotely European-sounding.
On top of that, in a nearby region now part of modern Chile, the natives had their own breed of chicken: the Araucana. These birds were/are not only feathered differently than European chickens (they have no tail and tufts of feathers around their ears) they lay blue and green eggs, the only breed of chicken in the world that does that. Could so unique a bird have evolved in a mere 30 years — some 1,000 miles away from the coast of Brazil? Many researchers have insisted not, and in fact a few have even advanced the idea that the New World had its own breed of indigenous chicken. I believe genetic analysis has thoroughly stomped all over that theory.
And indeed geneticists have lately tried to stomp all over the Polynesian theory as well. They’ve argued that chicken bones found in South American have genetic similarities to European/Indian/ Southeast Asian chickens. But then all chickens have genetic similarities to European/ Indian/ Southeast Asian chickens. Those same scientists also argue that chicken bones found on Easter Island are more genetically similar to chickens from Japan and China than to European/ Indian/ Southeast Asian chickens.
Yet to my mind that only shows that some chickens in Polynesia were Chinese in origin. It by no means proves that all chickens in Polynesia were Chinese in origin. Polynesia is a huge area…who knows what sort of chickens some populations of Polynesians might have kept — and brought with them to South America?
When you consider that prehistoric Polynesians are known to have introduced the sweet potato, bottle gourd and possibly even a type of canoe and fishhook to the Americas — and that they liked to bring animals like pigs, dogs and chickens with them when they traveled — the evidence seems awfully strong that chickens arrived in the Americas from the West. The DNA and carbon data may just need to catch up.
Still, it seems we’re a long way off in terms of answering the question definitively. Which means cockfighting of the academic stripe will continue to be good sport for years to come.
In all respect, genetics don’t really paint the full picture; especially when it comes to drifts. Like with dogs, the most diverse mitochondria DNA are from Chinese wolves; yet all the SNP are from the Middle Eastern clade.
The former can be easily explained: when you have a culture which revered in consumption of dogs, especially Chows, one breeds every dog they have. Also in Japan, killing dogs was illegal for awhile; and street dogs terrorized the inhabitants of the Tokugawa period. So, the dogs didn’t undergo much artificial selection pressure during that time frame as well– thus explains the diverse mtDNA.
However western breeds have been subjected to heavy culls, and strict selection for types. They are less diverse regarding mtDNA. The severe bottleneck is not accounted for in these studies searching for the origin of dogs.
Seeing most of all of today’s genes of domestic canines share most of their genotypes from Arabian wolves; it’s logical to conclude the primary domestication happened out west, not out east. Now that being said, dogs were being domesticated and re-domesticated throughout the eons everywhere. Just the ones who survived into the modern period bore the SNP and mtDNA which are being debated on.
So what does this have to do with chickens? It is entirely possible chickens were introduced by the Polynesians, but the types brought over by the Europeans happened to be more popular, more successful or whatever the scenario may be which lead one strain of chicken to be more common than the other; and this case, completely replaced the original population.
You sort of see this with cattle nowadays. The main breed now is Angus. Jersey cows are rare these days as beef, although it used to be more common; and the compositions from DNA analyses confirms most cattle are Angus.
Dave, this is why I glory in a readership that’s much more educated than I am. Thank you for writing this. It’s funny, I recently watched a pop-science show on dogs, from which I took away the notion that dogs are much more malleable than most animals in terms of their DNA…is that in fact true? I’m curious to know.
– Joe
Because of tandem repeats? Sure. You could double up on some alleles and create extreme features out of them. It’s why we have breeds like Shar Peis and Neapolitan Mastiff; people just kept doubling up on the regulators for wrinkly skins– the more copies one has of that regulator, the wrinklier they got. There are not a lot of genotypes regulating the appearance of a dog, but we know we could create more copies of a single genotype due to the flexible nature of tandem repeat. Most of our domesticated animals don’t do this.
But I think you’re referring to the notion of genetic diversity? With canines, they are quite diverse, unlike livestock; with exception of horses. Anytime one has a diverse gene pool with a domesticated species, it suggests multiple origins. When it’s implied like that, then it most probable there was multiple domestication. Although a lot of people still look for the “single origin event”. I don’t blame them, it’s the easiest concept to grasp.
But let tie this back to food. We know all sheep come from Mouflon because sheep themselves are quite inbred and shows less diversity compared to their wild cousins. Could had someone domesticated something like the Bighorn Sheep, as one anthropologist suggested it was possible for the Sioux? Sure, but they didn’t survive into modern time– so it’s really moot point.
People seem to forget genes and evolution are fluid. What we see a hundred years ago is not necessarily the same animal we see today. A lot seems to think once a new species or strain emerge, it’s static only for a different species to emerge from that one. However I guess the viewpoint depends whither one is a lumper or splitter.
Fascinating. In fact “single origin event” us a term I encountered quite a bit doing research for this post. I appreciate your shedding light on some of this for me. Thanks!
– Joe