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Upward Sun River Site
The Upward Sun River site, or Xaasaa Na’, is a Late Pleistocene archaeological site associated with the Paleo-Arctic tradition, located in the Tanana River Valley, Alaska. Dated to around 11,500 BP, Upward Sun River is the site of the oldest human remains discovered on the American side of Beringia. The site was first discovered in 2006. The layer with the human remains at Upward Sun River is most similar to the level 6 layer from Ushki Lake, Kamchatka. Both sites are the only Beringian burials found so far from that period. Etymology The name of the site, Upward Sun River, is a direct translation of the Middle Tanana name for the site, ''Xaasaa Na’''. The Middle Tanana name was recorded from the mother of a mother-daughter pair, two of the last remaining speakers of Middle Tanana, during an interview in the 1960s. Human remains The first excavation at Upward Sun River in 2010 yielded the cremated remains of a 3-year-old individual. The individual had been cremated insid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tanana Valley
The Tanana Valley is a lowland region in central Alaska in the United States, on the north side of the Alaska Range, where the Tanana River emerges from the mountains. Traditional inhabitants of the valley are Tanana Athabaskans of Alaskan Athabaskans. Climate The region experiences great extremes of temperature during the year. During the winter months, the air is prone to stratification due to temperature inversions, leading to thick fogs. During the summer, the surrounding plains are generally boglike, and include much permafrost and many pingos. Communities The Tanana Valley is the most populated area of Alaska north of the Alaska Range. Its largest city is Fairbanks. Other communities include: *College * Chena Hot Springs *Eielson AFB *Ester *Fort Wainwright * Fox * Manley Hot Springs * Nenana *North Pole * Tok * Two Rivers * Pleasant Valley *Salcha Archaeology According to James Q. Jacobs, Tanana Valley has the earliest evidence of human occupation in Alaska. "At lea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kennewick Man
Kennewick Man and Ancient One are the names generally given to the skeletal remains of a prehistoric Paleoamerican man found on a bank of the Columbia River in Kennewick, Washington, on July 28, 1996. It is one of the most complete ancient skeletons ever found. Radiocarbon tests on bone have shown it to date from 8,900 to 9,000 calibrated years before present,Preston, Douglas (September 2014)"The Kennewick Man Finally Freed to Share His Secrets" '' Smithsonian''. Retrieved November 8, 2014. but it was not until 2013 that ancient DNA analysis techniques had improved enough to shed light on the remains. The discovery led to controversy among scientists as well as Native American tribes for more than a decade. The Umatilla people and other tribes demanded that the remains be returned for reburial under the federal Native American Graves Protection and Repatriation Act (NAGPRA). The law was designed to return human remains and cultural objects which had long been unlawfully obt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
FADS2
Fatty acid desaturase 2 (FADS2) is encoded by the ''FADS2'' gene, the associated enzyme is sometimes known as FADS2 as well. Its main associated enzyme is Delta 6 desaturase (D6D) however the human enzyme been shown to also catalyze some delta-8 and delta-4 desaturases despite naming conventions. Function Fatty acid desaturase 2 is a member of the fatty acid desaturase (FADS) gene family. Desaturase enzymes cause desaturation of fatty acids through the introduction of double bonds between defined carbons of the fatty acyl chain. FADS family members are considered fusion products composed of an N-terminal cytochrome b5-like domain and a C-terminal multiple membrane-spanning desaturase portion, both of which are characterized by conserved histidine motifs. This gene is clustered with family members FADS1 and FADS2 at 11q12-q13.1; this cluster is thought to have arisen evolutionarily from gene duplication based on its similar exon/intron organization. Clinical significance I ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ectodysplasin A Receptor
Ectodysplasin A receptor (EDAR) is a protein that in humans is encoded by the EDAR gene. EDAR is a cell surface receptor for ectodysplasin A which plays an important role in the development of ectodermal tissues such as the skin. It is structurally related to members of the TNF receptor superfamily. Function ''EDAR'' and other genes provide instructions for making proteins that work together during embryonic development. These proteins form part of a signaling pathway that is critical for the interaction between two cell layers, the ectoderm and the mesoderm. In the early embryo, these cell layers form the basis for many of the body's organs and tissues. Ectoderm-mesoderm interactions are essential for the proper formation of several structures that arise from the ectoderm, including the skin, hair, nails, teeth, and sweat glands. Clinical significance Mutation in this gene have been associated with hypohidrotic ectodermal dysplasia, a disorder characterized by a lower densi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phenotype
In genetics, the phenotype () is the set of observable characteristics or traits of an organism. The term covers the organism's morphology or physical form and structure, its developmental processes, its biochemical and physiological properties, its behavior, and the products of behavior. An organism's phenotype results from two basic factors: the expression of an organism's genetic code, or its genotype, and the influence of environmental factors. Both factors may interact, further affecting phenotype. When two or more clearly different phenotypes exist in the same population of a species, the species is called polymorphic. A well-documented example of polymorphism is Labrador Retriever coloring; while the coat color depends on many genes, it is clearly seen in the environment as yellow, black, and brown. Richard Dawkins in 1978 and then again in his 1982 book '' The Extended Phenotype'' suggested that one can regard bird nests and other built structures such as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gene Flow
In population genetics, gene flow (also known as gene migration or geneflow and allele flow) is the transfer of genetic material from one population to another. If the rate of gene flow is high enough, then two populations will have equivalent allele frequencies and therefore can be considered a single effective population. It has been shown that it takes only "one migrant per generation" to prevent populations from diverging due to drift. Populations can diverge due to selection even when they are exchanging alleles, if the selection pressure is strong enough. Gene flow is an important mechanism for transferring genetic diversity among populations. Migrants change the distribution of genetic diversity among populations, by modifying allele frequencies (the proportion of members carrying a particular variant of a gene). High rates of gene flow can reduce the genetic differentiation between the two groups, increasing homogeneity. For this reason, gene flow has been thought to c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ancient Beringian
The Ancient Beringians (AB) is a specific archaeogenetic lineage, based on the genome of an infant found at the Upward Sun River site (dubbed USR1), dated to 11,500 years ago. The AB lineage diverged from the ''Ancestral Native American'' (ANA) lineage about 20,000 years ago. The ANA lineage was estimated as having been formed between 20,000 and 25,000 years ago by a mixture of East Asian and Ancient North Eurasian lineages, consistent with the model of the peopling of the Americas via Beringia during the Last Glacial Maximum. Research The Ancient Beringian lineage is extinct, and is not found as a contribution to modern indigenous lineages in Alaska. The 2018 study suggests that the AB lineage was replaced by or absorbed in a back-migration of NNA (see below) to Alaska. The modern Athabaskan populations are derived from an admixture of this NNA back-migration and a Paleo-Siberian (Early Paleo-Eskimo) lineage before about 2,500 years ago.Moreno-Mayar et al. (2018), fig. 3Suppleme ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Haplogroup B (mtDNA)
In human mitochondrial genetics, haplogroup B is a human mitochondrial DNA (mtDNA) haplogroup. Origin Haplogroup B is believed to have arisen in Asia some 50,000 years before present. Its ancestral haplogroup was haplogroup R. The greatest variety of haplogroup B is in China. It is therefore likely that it underwent its earliest diversification in mainland East or South East Asia.Yong-Gang Yao et al. 2001Phylogeographic Differentiation of Mitochondrial DNA in Han ChineseAm J Hum Genet. 2002 March; 70(3): 635–651 Distribution Basal B was found in Upper Paleolithic Tianyuan man. Haplogroup B is now most common among populations native to Southeast Asia, as well as speakers of Sino-Tibetan languages and Austronesian languages. A subclade of B4b (which is sometimes labeled B2) is one of five haplogroups found among the indigenous peoples of the Americas, the others being A, C, D, and X. Because the migration to the Americas by the ancestors of indigenous Americans is gene ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Haplogroup C (mtDNA)
In human mitochondrial genetics, Haplogroup C is a human mitochondrial DNA (mtDNA) haplogroup. Origin Haplogroup C is believed to have arisen somewhere between the Caspian Sea and Lake Baikal some 24,000 years before present. It is a descendant of the haplogroup M. Haplogroup C shares six mutations downstream of the MRCA of haplogroup M with haplogroup Z and five mutations downstream of the MRCA of haplogroup M with other members of haplogroup M8. This macro-haplogroup is known as haplogroup M8'CZ or simply as haplogroup M8. Distribution Haplogroup C is found in Northeast Asia (including Siberia) and the Americas. In Eurasia, Haplogroup C is especially frequent among populations of arctic Siberia, such as Nganasans, Dolgans, Yakuts, Evenks, Evens, Yukaghirs, and Koryaks. Haplogroup C is one of five mtDNA haplogroups found in the indigenous peoples of the Americas, the others being A, B, D, and X. The subclades C1b, C1c, C1d, and C4c are found in the first people ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sampling Variation
In statistics, sampling errors are incurred when the statistical characteristics of a population are estimated from a subset, or sample, of that population. Since the sample does not include all members of the population, statistics of the sample (often known as estimators), such as means and quartiles, generally differ from the statistics of the entire population (known as parameters). The difference between the sample statistic and population parameter is considered the sampling error.Sarndal, Swenson, and Wretman (1992), Model Assisted Survey Sampling, Springer-Verlag, For example, if one measures the height of a thousand individuals from a population of one million, the average height of the thousand is typically not the same as the average height of all one million people in the country. Since sampling is almost always done to estimate population parameters that are unknown, by definition exact measurement of the sampling errors will not be possible; however they can often be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Denisovan
The Denisovans or Denisova hominins ) are an extinct species or subspecies of archaic human that ranged across Asia during the Lower and Middle Paleolithic. Denisovans are known from few physical remains and consequently, most of what is known about them comes from DNA evidence. No formal species name has been established pending more complete fossil material. The first identification of a Denisovan individual occurred in 2010, based on mitochondrial DNA (mtDNA) extracted from a juvenile female finger bone excavated from the Siberian Denisova Cave in the Altai Mountains in 2008. Nuclear DNA indicates close affinities with Neanderthals. The cave was also periodically inhabited by Neanderthals, but it is unclear whether Neanderthals and Denisovans ever cohabited in the cave. Additional specimens from Denisova Cave were subsequently identified, as was a single specimen from the Baishiya Karst Cave on the Tibetan Plateau. DNA evidence suggests they had dark skin, eyes, and hair, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
