AbstractThere is a consensus that modern
humans arrived in the Americas 15,000–20,000 y ago during the Late
Pleistocene, most probably
from northeast Asia through Beringia.
However, there is still debate about the time of entry and number of
including apparent inconsistencies between
genetic and morphological data on Paleoamericans. Here we report the
of mitochondrial sequences belonging to
haplogroups characteristic of Polynesians in DNA extracted from ancient
the now extinct Botocudo Indians from
Brazil. The identification of these two Polynesian haplogroups was
confirmed in independent
replications in Brazil and Denmark,
ensuring reliability of the data. Parallel analysis of 12 other Botocudo
only the well-known Amerindian mtDNA
haplogroup C1. Potential scenarios to try to help understand these
results are presented
and discussed. The findings of this study
may be relevant for the understanding of the pre-Columbian and/or
peopling of the Americas.
Category Archives: Polynesians
|Queen Liliuokalani of Hawaii in her youth|
Native Hawaiians still make up some 38% of the population of Hawaii but most of them have mixed ancestry nowadays. This new study may help to understand them better and also includes some interesting findings about the overall origins of Polynesians, whose Melanesian ancestry is revealed as very significant.
The population genetic structure of Native Hawaiians has yet to be comprehensively studied, and the ancestral origins of Polynesians remain in question. In this study, we utilized high-resolution genome-wide SNP data and mitochondrial genomes of 148 and 160 Native Hawaiians, respectively, to characterize their population structure of the nuclear and mitochondrial genomes, ancestral origins, and population expansion. Native Hawaiians, who self-reported full Native Hawaiian heritage, demonstrated 78% Native Hawaiian, 11.5% European, and 7.8% Asian ancestry with 99% belonging to the B4 mitochondrial haplogroup. The estimated proportions of Native Hawaiian ancestry for those who reported mixed ancestry (i.e. 75% and 50% Native Hawaiian heritage) were found to be consistent with their self-reported heritage. A significant proportion of Melanesian ancestry (mean = 32%) was estimated in 100% self-reported Native Hawaiians in an ADMIXTURE analysis of Asian, Melanesian, and Native Hawaiian populations of K = 2, where K denotes the number of ancestral populations. This notable proportion of Melanesian admixture supports the “Slow-Boat” model of migration of ancestral Polynesian populations from East Asia to the Pacific Islands. In addition, approximately 1,300 years ago a single, strong expansion of the Native Hawaiian population was estimated. By providing important insight into the underlying population structure of Native Hawaiians, this study lays the foundation for future genetic association studies of this U.S. minority population.
Figure 1. ADMIXTURE clustering of Native Hawaiians for K = 5 (A) and K = 6 (B). Figures 1A and 1B illustrate the clustering of Native Hawaiians and HGDP samples based on GWAS data.
|Figure 4. Supervised ADMIXTURE results for K = 2…|
The dispersal of modern humans across the globe began ∼65,000 y ago when people first left Africa and culminated with the settlement of East Polynesia, which occurred in the last 1,000 y. With the arrival of Polynesian canoes only 750 y ago, Aotearoa/New Zealand became the last major landmass to be permanently settled by humans. We present here complete mitochondrial genome sequences of the likely founding population of Aotearoa/New Zealand recovered from the archaeological site of Wairau Bar. These data represent complete mitochondrial genome sequences from ancient Polynesian voyagers and provide insights into the genetic diversity of human populations in the Pacific at the time of the settlement of East Polynesia.
A recent reevaluation of the dates for the colonization of East Polynesia suggests that, contrary to earlier studies positing a relatively long (2,000 y) chronology for the region, the settlement of most of East Polynesia occurred rapidly, in the period from A.D. ∼1190–1290 (22). The authors determined that the expansion event occurred from the Society Islands, which were only settled 70–265 y previously. This rapid and recent expansion event, they argue, explains the “remarkable uniformity of East Polynesian culture, human biology and language” (22).
Wilmshurst JM, Hunt TL, Lipo CP, Anderson AJ (2011) High-precision radiocarbon dating shows recent and rapid initial human colonization of East Polynesia. Proc Natl Acad Sci USA 108(5):1815–1820.