vrijdag 19 november 2010

Iceland (Ísland)...

First Americans 'reached Europe five centuries before Columbus discoveries'Scientists claim first Americans arrived long before Columbus bumped into an island in the Bahamas in 1492

Christopher Columbus did not introduce the first native Americans to Europe, according to new research.

When Christopher Columbus paraded his newly discovered American Indians through the streets of Spanish towns at the end of the 15th century, he was not in fact introducing the first native Americans to Europe, according to new research.

Scientists who have studied the genetic past of an Icelandic family now claim the first Americans reached Europe a full five centuries before Columbus bumped into an island in the Bahamas during his first voyage of discovery in 1492.

Researchers said today that a woman from the Americas probably arrived in Iceland 1,000 years ago, leaving behind genes that are reflected in about 80 Icelanders today.

The link was first detected among inhabitants of Iceland, home to one of the most thorough gene-mapping programs in the world, several years ago.

Initial suggestions that the genes may have arrived via Asia were ruled out after samples showed they had been in Iceland since the early 18th century, before Asian genes began appearing among Icelanders.

Investigators discovered the genes could be traced to common ancestors in the south of Iceland, near the Vatnajˆkull glacier, in around 1710.

"As the island was practically isolated from the 10th century onwards, the most probable hypothesis is that these genes correspond to an Amerindian woman who was taken from America by the Vikings some time around the year 1000," Carles Lalueza-Fox, of the Pompeu Fabra university in Spain, said.

Norse sagas suggest the Vikings discovered the Americas centuries before Columbus got there in 1492.

A Viking settlement at L'Anse aux Meadows, in the eastern Canadian region of Terranova, is thought to date to the 11th century.

Researchers said they would keep trying to determine when the Amerindian genes first arrived in Iceland.

"So far, we have got back to the early 18th century, but it would be interesting to find the same sequence further back in Icelandic history," Lalueza-Fox said.

The genetic research, made public by Spain's Centre for Scientific Research, was due to be published in the American Journal of Physical Anthropology.

Conclusions of the scientific article:
We have identified four different matrilines carrying the C1e lineage in the Icelandic mtDNA pool, with the earliest known ancestors of each born: 1720 (1), 1740 (2), 1710 (3), and 1720 (4). All four ancestors were geographical neighbors in Iceland, with 1, 2, and 3 from the county of Rangarvallarsysla and 4 from the adjacent county of Vestur Skaftafellssysla. This supports the notion of a matrilineal MRCA for the four ancestors born in Iceland after the time of settlement in 870. If it is assumed that ancestors 1, 2, 3, and 4 were all sisters or very close matrilineal relatives, then the MRCA and latest possible arrival date of the C1e lineage in Iceland could be dated to around or just before 1700. However, there are at least three reasons to assume an earlier entry date for the Icelandic C1e lineage. First, even if it is assumed that the MRCA of 1, 2, 3, and 4 was born close to 1700, the lineage could still have been present in Iceland for hundreds of years before that time. Indeed, although most matrilines in contemporary Icelanders are expected to be derived from the settlement period, only 8% of them can be traced beyond 1500, due to the cumulative impact of missing genealogical data. Second, it is unlikely that we have identified all C1e matrilines in the Icelandic mtDNA pool and each additional matriline increases the likelihood of an earlier date for the MRCA and therefore an earlier date for the most conservative entry date estimate. Third, although the fixed mutation at position 13567 in matriline 4 does not rule out a close relationship between its ancestor and those of 1, 2, and 3, it is more consistent with an MRCA some generations earlier because of the slow rate of mutation in the coding region. Thus, it is possible and perhaps even probable that the C1e lineage entered the Icelandic mtDNA pool prior to Columbus's rediscovery of the Americas.

Although the complete sequence of the Icelandic C1 lineage fully resolved its position in the human mtDNA tree, the mystery surrounding the lineage's geographical origin has only deepened. This is because there are no other known human mtDNA sequences that belong to C1e out of the 6747 complete sequences available in the literature (van Oven and Kayser, 2009). A simple argument in favor of a Native American origin of C1e is the fact that three of the four previously characterized C1 subclades are associated with these groups and the vast majority of C1 sequences in the literature have been sampled from individuals of Native American ancestry. Most of these sequences are limited to the control region, which includes sites that are characteristic of C1, but none that can be reliably used to determine membership in C1e. We identified 980 C1 sequences in a database of 32,193 control region sequences from the literature, of which 152 could be assigned to C1 subclades based on control region mutations (16356C for C1a, 493G for C1b, and 16051G for C1d). An additional 274 sequences that did not include all these sites were inferred to be members of C1a, C1b, or C1d on the basis of shared rare mutations with longer C1 sequences that could be directly assigned to these subclades. From the remaining unclassified 554 C1 sequences, we attempted to pick out possible C1e candidates, using the criteria of one mutational difference from C1e when sequences were available for only hypervariable segment 1 (HVS1) or 2 (HVS2) and two mutational differences when both HVS1 and HVS2 sequences were available. The result was a shortlist of 276 sequences that we suggest be checked first for C1e coding region mutations (Supp. Info. Table S3). We note that for the sequences for which geographical information is available, all but two were sampled from individuals with Native American ancestry—i.e. from the Canary Islands and Germany. The German sequence (Pfeiffer et al., 2001) represents a perfect match to the Icelandic C1e for the short HVS1 fragment spanning sites 16024–16365. This raises the intriguing, but perhaps unlikely, hypothesis that C1e is a European-specific subclade of C1, following the precedent of the European and Native American subclades of mtDNA haplogroup X2 (Brown et al., 1998; Reidla et al., 2003). However, given the dense sampling of mtDNA variation in European populations, it is clear that C1e is exceedingly rare, a fact that weighs against a hypothesis of antiquity in Europe.

Assuming that C1e has a Native American origin, it seems most likely that it would be found in individuals that trace their matrilineal ancestry to the north-eastern coastline of North America, where the pre-Columbian contact with Icelanders may have taken place. This poses a problem for the hunt of C1e in the Americas, as Native Americans from North America are somewhat undersampled compared to groups from other regions of the world and may contain many mtDNA lineages that have not yet been encountered in the literature (Malhi et al., 2010). One likely candidate C1e sequence, found in individuals with Native American matrilineal ancestry from Quebec in Canada (Moreau et al., 2009), was quickly ruled out. It exhibited the same control region mutations as the Icelandic C1e sequence, with one additional 150T mutation. Further examination ruled out C1e status, based on a complete Canadian sequence (EU431086 from Achilli et al., 2008) that carried the same set of control region mutations, but was classified as C1c based on coding region mutations.

Given the rather drastic population size reductions that resulted from the actions of Europeans after 1492, it is quite possible that the C1e lineage was once carried by, but has now been lost from, contemporary individuals with Native American matrilineal ancestry. Thus, ancient DNA may play an important role in determining the origin of the C1e lineage. It is therefore intriguing to note that several ancient mtDNA sequences from Native Americans are found in Supporting Information Table S3. Among them are sequences from the skeletal remains of Oneota individuals from a cemetery in Illinois (Stone and Stoneking, 1998) and individuals from the Caribbean islands (Lalueza-Fox et al., 2001). From the latter study, a bone sample from a pre-Columbian Taino from Hispaniola (Lalueza-Fox et al., 2001) was tested by C.L.F. in Barcelona for five coding-region mutations characteristic of the Icelandic C1e lineage (Supp. Info. Table S4 and supplementary methods), but it was revealed to carry none of them.

The mystery surrounding the geographical origin of the Icelandic C1e lineage will remain until additional members are found in other populations—ancient or contemporary. Until then, we propose that the most likely hypothesis is that the Icelandic voyages to the Eastern coastline of the Americas resulted in the migration of at least one Native American woman carrying the C1e lineage to Iceland around the year 1000.

Ebenesersdóttir, S. S., Sigurðsson, Á., Sánchez-Quinto, F., Lalueza-Fox, C., Stefánsson, K. and Helgason, A. , A new subclade of mtDNA haplogroup C1 found in icelanders: Evidence of pre-columbian contact?. American Journal of Physical Anthropology, n/a. doi: 10.1002/ajpa.21419

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