Transportation to the New World is a big topic for debate. 提出问题If the early Americans did cruise巡航 around the continent in canoes and kayaks, might the first settlers have arrived by boat as well? For decades the archaeological community rejected this notion (Ice Agehunters could never have carried all their weapons and left over mammoth meat in such tiny boats!), but in recent years the idea has gathered more support.旧观点反对经由海路假说
One reason for the shift: the nagging困扰的 problem of just how fast people can make the journey from Alaska toTierra del Fuego. 旧观点的问题症结点Consider Dillehay's 14,700-year-old Monte Verde site. According to the previously accepted timeline, people could have made the journey from Asia on foot no earlier than 15,700 years ago(before this time, the ice sheets extending from the North Pole covered Alaskaand Canada completely, making a land passage impossible). If this entry date is correct, the Monte Verde find would indicate that the first settlers had to make the 12,000 -mile trip through two continents in only 1,000 years. In archaeological time, that's as fast as Marion Jones(地球上跑得最快的女人). 提出反对旧观点的理由:行走速度太快? One way to achieve this pace , however,would be by traveling along the Pacific coastlines of North and SouthAmerica in boats. 转折, F提出海路假说新观点Knut Fladmark, a professor of archaeology at Simon Fraser University in Burnaby, BC, first suggested this possibility in the 1970s and remains an advocate of a coastal entry into the Americas. If people had a reason to keep moving, he says, they could have traversed both continents in 100 years. 支持理由:速度符合Fladmark estimates that traveling at a rate of 200 miles a month would have been quite reasonable; the settlers no doubt stopped during winter months and probably stayed in some spots for a generation or so if the local resourceswere particularly tempting. Fladmark's theory, though enticing won't be easy to prove. 让步,提出缺陷Rising sea levels from the melting Ice Age glaciers in undated thousands of square miles along the Pacific coasts of both continents. Any early sites near the ocean that were inhabited before 13,000 years ago would now be deep underwater. 新观点的弱点Recently a few enterprising researchers have attempted to dredge挖出 up artifacts from below the Pacific. In 1997, for example, Daryl Fedje, an archaeologist with Parks Canada (which runs that country's national parks system), led a team that pulled up a small stone tool from 160 feet underwater just off the coast of British Columbia. 提出证据证明新观点The single tool, which Fedje estimates to be around 10,200 years old, does establish that people once lived on the now submerged land but reveals little about the culture there. Excavating underwater sites might turn out to be the only way to prove when humans first arrived on this continent.提出对证据的质疑? And for many researchers this is still a very open question 因为证据力不足，海路说尚未定论, with answers ranging from 15,000 years ago to as far back as 50,000 years ago. When Fladmark first proposed the idea of a coastal migration, the entry date of 14,000 or 15,000 years ago was orthodoxy.公认的,持普遍赞同的