The sweet potato is a good question," conceded Cooper. "The bottle gourd was recently shown to have probably crossed to South America by marine currents, not human trade, as previously assumed, so I also wonder about the potato's ability to be dispersed in that fashion."
If the presence of pre-Columbian chickens is a good indicator that Polynesians succeeded in crossing the Pacific, the absence of one of their old shipmates—Rattus exulans, the Pacific rat—makes an equally compelling case against it. The Pacific rat is known to have traveled everywhere with their Polynesian hosts, and wherever they landed they invariably established thriving local rat populations that live on to this day. There are no Pacific rats in South America.
For her part, Storey stands by the pre-Columbian dates she and her team obtained for the chicken bones in Chile. She argues that the DNA results in the study released this week are far from conclusive.
"Indeed, the bulk of their research focuses on modern DNA," she said. "Using modern DNA to understand what people were doing in the past is like sampling a group of commuters at a London Tube station at rush hour. The DNA you get is unlikely to provide much useful information on the pre-Roman population of London."
As humans moved around the world, they brought chickens along with them. So modern chicken populations aren't necessarily representative of past populations, Storey said. "We know from his journals [that] Cook moved chickens all over the Pacific, as did other Europeans, so DNA from chickens living on Pacific islands today has little to tell us about what people were doing in Polynesia, the Pacific, and in Southeast Asia before A.D. 1600."
The new research appears to have laid these old bones to rest, but questions remain. One thing is certain: If the dates of the 2007 study are correct and there were indeed chickens in pre-Columbian South America, they had to come from somewhere. There is also the matter of the sweet potato, a definite South American native, which had spread throughout the Pacific by the time Europeans arrived on the scene.
The sweet potato is a good question," conceded Cooper. "The bottle gourd was recently shown to have probably crossed to South America by marine currents, not human trade, as previously assumed, so I also wonder about the potato's ability to be dispersed in that fashion."If the presence of pre-Columbian chickens is a good indicator that Polynesians succeeded in crossing the Pacific, the absence of one of their old shipmates—Rattus exulans, the Pacific rat—makes an equally compelling case against it. The Pacific rat is known to have traveled everywhere with their Polynesian hosts, and wherever they landed they invariably established thriving local rat populations that live on to this day. There are no Pacific rats in South America.For her part, Storey stands by the pre-Columbian dates she and her team obtained for the chicken bones in Chile. She argues that the DNA results in the study released this week are far from conclusive."Indeed, the bulk of their research focuses on modern DNA," she said. "Using modern DNA to understand what people were doing in the past is like sampling a group of commuters at a London Tube station at rush hour. The DNA you get is unlikely to provide much useful information on the pre-Roman population of London."As humans moved around the world, they brought chickens along with them. So modern chicken populations aren't necessarily representative of past populations, Storey said. "We know from his journals [that] Cook moved chickens all over the Pacific, as did other Europeans, so DNA from chickens living on Pacific islands today has little to tell us about what people were doing in Polynesia, the Pacific, and in Southeast Asia before A.D. 1600."The new research appears to have laid these old bones to rest, but questions remain. One thing is certain: If the dates of the 2007 study are correct and there were indeed chickens in pre-Columbian South America, they had to come from somewhere. There is also the matter of the sweet potato, a definite South American native, which had spread throughout the Pacific by the time Europeans arrived on the scene.
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