遷徙新大陸模型

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"Three maps of prehistoric America. (A)  then gradual population expansion of the Amerind ancestors from their East Central Asian gene pool (blue arrow). (B) Proto-Amerind occupation of Beringia with little to no population growth for ≈20,000 years. (C) Rapid colonization of the New World by a founder group migrating southward through the ice-free, inland corridor between the eastern Laurentide and western Cordilleran Ice Sheets (green arrow) and/or along the Pacific coast (red arrow). In (B), the exposed seafloor is shown at its greatest extent during the last glacial maximum at ≈20–18 kya [25]. In (A) and (C), the exposed seafloor is depicted at ≈40 kya and ≈16 kya, when prehistoric sea levels were comparable.  A scaled-down version of Beringia today (60% reduction of A–C) is presented in the lower left corner. This smaller map highlights the Bering Strait that has geographically separated the New World from Asia since ≈11–10 kya."
早期人类迁徙和殖民美洲的三个阶段图

人类在何时以何种方式迁入美洲的问题成引发了人类学家考古学家巨大的兴趣,并且成为几个世纪以来一直争论不休的话题。学术界给出了许多古印地安人在美洲定居的模型。现代生物化学技术和考古学的结合也极大地促进了人对于这个问题的认识。

目前,对于这个问题的解答工作主要涉及到以下四个互相关联的学科,考古学人类体格学DNA分析学以及语言学。目前,学界大体认可,美洲大陆第一批移民是自白令海峡迁徙而来的亚洲的族群。然而,移民的模式、时间以及进入美洲的人为何种亚洲族群至今尚不明确。[1]

近年来,学术界不断用已经掌握的方法对一些已经建立起来的理论进行进一步证实或者是证伪,这些理论种较为出名的是认为克洛维斯人是第一个到达美洲的人类种群。[2] 随着发现的深入,过去的假设被重新审查并且新的理论随即被提出。考古证据表明,古印地安人大规模的扩张在上个冰河时期末期,或者更精确地说,是末次冰盛期(Late Glacial Maixmum),也就是距今16,500–13,000年前。[3]

各派意见综述[编辑]

Flèches préhistoriques amérindiennes, conservées à Washington

迁徙模型在时间上大致分为两派。[4][5] 第一种叫做"短时理论"(short chronology theory),短时理论认为人类第一次从阿拉斯加迁徙至新大陆的发生晚于距今15,000 – 17,000年前,之后展开了波浪式的移民推进(waves of immigrants)。[6][7] 第二种叫做"长时理论"(long chronology theory)其认为,第一批人类到达美洲大陆所在的半球时间要远早于15,000 – 17,000年前,他们认为可能的时间为 21,000–40,000年前。[8][9] ,然后才是第二波巨大的移民潮。[10][11][12]

一个引发巨大争论的原因是,南部美洲和北部美洲的古印地安人定居点在考古证据上的不连续。一个大体上统一的考古学文化在北部和中部美洲被发现,距今至少有13,500年的历史,考古学家称之为克洛維斯文化[13] 然而,同一时代的南美洲的据点就缺乏这样的一致性,拥有更大的文化多样性。考古学家认为,"克洛维斯先至论"和古印地安人时间框架都不足以解释复杂的美洲石器时代(lithic stage)工具是如何在南美洲出现的。一些理论学家正在寻求一种可以整合南北美洲考古记录的新的殖民模型。

对美洲土著的基因研究发现,“殖民缔造人群”(colonizing founder)可能是单一祖先人群。基于Y染色体微卫星中的美洲单倍型类群Q1a3a(Y-DNA)分叉的时间推算,这个单一祖先人群出现在距今10,000到15,000年前。而这个单一祖先人群的很有可能来自白令海峡 [14][15][16][17][18] [5][19] 这一点仍然不足以说明,在此之前,抑或其他基因也曾试图在这片土地上繁衍并且以失败告终。因为基因测试只能基于现存人口的遗传信息进行。[5]

当白令大陆桥露出海平面的时候,从东北亚步行至阿拉斯加是相对容易的。然而从阿拉斯加到其他北美洲地区路途却十分艰难。我们猜测主要有两个可能的路径,沿大西洋海岸往南,或者是逻辑山脉东侧的内陆通道—麦肯锡走廊(Mackenzie Corridor)[17]。在Laurentide和Corilleran冰盖最大的时候,这两条道路都是极其容易的。Corilleran冰盖西起太平洋,东至Laurentide冰盖,也就是今天加拿大的不列颠-哥伦比亚省和阿尔伯塔省的交界。地理学证据证明,太平洋沿岸路保持畅通是在公元前21,000年之前和公元前13,000年之后。在上一个冰河时期中最冷的一千年,大致在距今23,000到19,000年之前,冰川是的道路充满危险。即使使用船只也十分困难,因为水体中到处都是冰山。况且尚无古代海岸线上有船只的考古证据。在这段时间以前,这些通路是没有结冰的。另外,当气候温暖的时候,土地上被植被覆盖,早期古印第安人可以在这里补充给养,缝补衣服帐篷,以及重置工具等等。[15]海岸线和船只理论有一个模糊的假设,那就是一个在北美大陆上的古印第安人可能已经不是纯粹的陆地狩猎者,而已经习惯于航海或者半航海的生活。[12]另外,”白令人”(北阿拉斯加人)甚至很有可能是由于被上一次冰河期的逼迫下,在20,000年前,向北美内陆和海岸线迁徙, [20] 并且留下占据某些特定局部区域的考古证据。然而,除非他们最终在最后一次冰期结束后仍然生存繁衍,不然他们就不能被当作是“缔造人群”(founding population)。[21]



陆桥论[编辑]

也被称为白令海峡沿岸论(Bering Strait Theory)或者白令陆桥论(Beringia)。自从1930年起,陆桥论被广泛接受。而早在1590年,耶稣会学者José de Acosta就已经提出这样的初步假设。[22] 陆桥论主张,第一批美洲移民是从西伯利亚来到阿拉斯加。原因则很可能是追赶迁徙的牛群。我们可以通过收集氧的同位素深海泥土的取样发现,在最后一个更新世,也就是距今50,000-10,000年前,海平面比现在低60米左右。那样就有一段至少1000英里宽的大陆桥连接西伯利亚和阿拉斯加。也就是这段时间内,那些追逐大型猎物的猎人在距今大约12,000年前的时候通过大陆桥到达美洲,并且在距今11,000年前最终到达南美洲的最南端。

Shrinking of the Bering land bridge
人类自白令海峡往南移民的无障碍通路表[23]
时间 公元前 B.C. 白令路桥 "大陆桥" 海岸线 Mackenzie 走廊
38,000–34,000 可通行 (开启) 开启 关闭
34,000–30,000 淹没 (关闭) 开启 开启
30,000–22,000 可通行 (开启) 关闭 开启
22,000–15,000 可通行 (开启) 开启 关闭
15,000–today 淹没 (关闭) 开启 开启

基因与血型[编辑]

Schematic illustration of maternal geneflow in and out of Beringia.Colours of the arrows correspond to approximate timing of the events and are decoded in the coloured time-bar. The initial peopling of Berinigia (depicted in light yellow) was followed by a standstill after which the ancestors of indigenous Americans spread swiftly all over the New World while some of the Beringian maternal lineages–C1a-spread westwards. More recent (shown in green) genetic exchange is manifested by back-migration of A2a into Siberia and the spread of D2a into north-eastern America that post-dated the initial peopling of the New World.
Schematic illustration of maternal (mtDNA) gene-flow in and out of Beringia.

学界早在1920年代就指出,在哥伦布到达新大陆前,美洲的绝大部分人口为O型血以及很小部分在北方的A型人口。之后,由Cavalli-Sforza为先驱,开始通过对更早的历史人口迁徙记录更深入的统计学和基因学基因学研究。Jacob BronowskiThe Ascent of Men(1973)中这样说道,

"我们没有理由不相信,第一批来到美洲的一些是来自一个较小且具有亲属关系的O型血人群,然后他们在美洲大陆上繁衍生息,并且向南扩张。之后到来的,同样是一个较小的人群,但是混合了A型和O型血,来到北美洲。"[24]

现代美洲基因学则主要研究人类Y染色体DNA单倍型类群人类粒线体单倍群。基因图谱显示两种迥然不同的基因(genetic episodes),也就是美洲土著和欧洲殖民者的基因。决定前者的基因谱数的是合子的突变和基本单倍型。[5][25][26] [25]由此说明,新大陆上的居民由小部分基础人群(found population)一开始从白令路桥一步步繁衍而来。[5][16][21]微卫星在南美洲的多样性和Y种系特异性基因的分布表明,一个特定印地安人在迁徙在美洲的一开始就被孤立起来。[27] ,其中就包括 Na-Dené, 因纽特人 以及 阿拉斯加土著。在这些人群中发生了和其他美洲土著人群完全不同的基因突变。前者出现了haplogroup Q (Y-DNA) mutations,而后者则多为mtDNA 和atDNA突变。[28][29][30] 这也就暗示了那些最早到达美洲大陆最北端和格林兰的人群恰恰后来的移民而非一开始到达美洲的人群。[31][32]


考古,地理和基因学证据选录[编辑]

40,000 B.C. – 25,000 B.C.
30,000–20,000年前:
  • 70-80年代,考古学家Jacques Cinq-Mars在育空鯥洞(Bluefish Caves)发现有人工雕琢痕迹的猛犸象骨。[34] [35]
  • 2004年,南卡罗来那考古和人类学学院的Albert Goodyear在topper,(Allendale, county, South Carolina),通过炭的同位素法发现了一块早于科利维斯文化的燃烧过的木炭。 [36]然而也有人认为生成这些木炭的原因是森林火灾。[36]也有人对此表示异议。[12][37]
  • 50年代,由于在冰川沙石(Grimshaw, Bow River 以及Lethbridge Alberta附近)下发现了石质器具,地理学家由此认为在Alberta和Laurentide ice sheet之间有一个没有为冰雪所覆盖的走廊。 据此,也表明在冰河世纪以前可能已经有游牧民族在这里生活。[38]1961年一块儿童的头骨在Taber,Alberta附近被发现,是迄今在Alberta发现的最古老的居民。[39]也有人对此表示异议。[40]
  • 剑桥DNA项目组估计人类到达美洲大约是25,000年以前。[41]其他的基因学家对于年代的的估计意见分歧很大,认为美洲的人群可能在范围在21,000年到42,000年间。[11]
  • 西伯利亚猛犸象猎人被认为可能通过无冰走廊到达过北极的深处。这个理论于1970年被地理学家提出。他们的证据是对泥土样本的分析。分析的结论是所有的冰层的年龄不超过17,000。由此说明,无冰走廊的存在。[15]
23,000–16,500 years ago:
  • The Ice Age entombs the northern hemisphere in glaciers, cutting off routes from Siberia to the south.[42]
  • 2002 the presence of the X haplogroup was found in a small percentage of modern indigenous Americans that is known to exist in a few locations in Europe and the Middle East. Subsequent research indicated that this DNA was not the result of genetic mixing after Columbus. However, the time estimates on haplogroup X entering Americas is around 15,000 to 20,000 years ago.[43]
  • Genetic evidence (2007–2009) suggests the Beringia population's first genetic diversification from Asian populations occurred.[44] An article in the American Journal of Human Genetics states "Here we show, by using 86 complete mitochondrial genomes, that all Native American haplogroups, including haplogroup X, were part of a single founding population.[11][44][45]
16,500–13,000 years ago:
  • Receding glaciers reopened an ice-free corridor through Canada between Alaska and the rest of the Americas. Massive flooding would have created large lakes covering vast areas of north America with glacial waters.[46]
  • Age estimates based on Y-chromosome micro-satellite place diversity of the so called "American Haplo" Q1a3a1 at around 10,000 to 15,000 years ago.[5]
  • Mass extinction of large fauna begins due to hunting and perhaps climate change. The dire wolf, Smilodon, American lion, giant beaver, ground sloths, mammoths, American mastodon, American camel and American equine all become extinct by 11,000 years ago.[47][48]
  • Pre-Clovis sites uncovered from 1973 to 1978 Meadowcroft Rockshelter in Pennsylvania site indicated occupancy as early as 16,000 years ago and possibly as long as 19,000 years ago. Dates in excess of 19,000 years have been claimed for the deepest occupation layer uncovered.[49]
  • pre-Clovis sites found in Monte Verde, located along Chinchihuapi Creek, in Chile. A crew of eighty people, led by Tom Dillehay of the University of Kentucky, excavated the site from 1977 to 1985.[50] A coastal migration could explain how people arrived in Monte Verde.[50]
  • 2000, archaeologists say people were living at Cactus Hill, Virginia where stone tools and charcoal from a fire pit are found.[51]
15,000–13,000 years ago:
  • The Taima Taima mastodon kill/butchering site in Falcon, Venezuela was first excavated by J.M. Cruxent in the 1960s and 1970s. It is one of the earliest archaeological sites that is pre-Clovis. In 1976 a broken El Jobo point (red arrow) was found inside the pubic cavity of a partially disarticulated and butchered young mastodon whose bones had been cut, with a jasper flake found near the left ulna of the animal.[52]
  • Peñon woman found by an ancient lake bed near Mexico City in 1959.[53]
  • El Abra sites located in the valley east of the city of Zipaquirá, Colombia. First excavated by Gonzalo Correal and associates in the late 1970s and early 1980s. 3,072 pieces found indicate it was inhabited continuously for over 7,000 years.[54]
  • At Paisley Caves in the Cascade Range of Oregon, archaeologists find a scattering of human coprolites, or fossil feces in 2003.[55] The mitochondrial DNA extracted from coprolites linked the cave dwellers to two genetic groups of early Americans that arose 14,000 to 18,000 years ago.[55] These two genetic groups were the founding Paleo-Indians and later Na-Dené migration.[16][28]
13,500–12,000 years ago:
  • The Ice Age is ending, melting glaciers have raised sea levels 120 meters and submerged the land bridge between Alaska and Siberia. Geologic evidence indicates that by 11,500 years ago, the Cordilleran and Laurentide ice sheets had retreated far enough to open a habitable ice-free corridor between them. The exposed land was dry and probably restored enough to support plants and animals, which the migrating hunter-gatherer followed.[56]
  • Clovis theory – People were living near Clovis, New Mexico where tools from this era were found in the 1930s. This find gave rise to the widely held "Clovis First" theory that people spread through the Americas only after the Ice Age.[57] The Clovis culture was believed replaced by several more localized regional cultures, such as the Folsom tradition, from the time of the Younger Dryas cold climate period.[11]
  • Peru coastal region inhabitants fished with nets and bone hooks, collecting seafood such as crabs and sea urchins.[58]
12,000–10,000 years ago:
  • Ice age over, climate similar to present temperatures. Old migration theories believe first widespread migration in South America and subsequently a dramatic rise in population all over the Americas, introduced in the 1930s.[59]
  • The Maritimes of Canada are settled by Paleo-Indians. Sites in and around Belmont, Nova Scotia have evidence indicating small seasonal hunting camps, perhaps re-visited over many generations.[60]
  • Luzia Woman's skull and other bones excavated in the Lagoa Santa, Brazil area by French archaeologist Annette Laming-Emperaire in the 1970s.[61] By 2006, Lagoa Santa sites had produced no fewer than 75 well-preserved ancient skulls.[61]
  • 1994, University of California, Riverside anthropologist R. Erv Taylor examined seventeen of the Spirit Cave artifacts near Fallon, Nevada from the 1940s using mass spectrometry. The results indicated that a mummy was approximately 9,400–10,200 years old — older than any previously known North American mummy.[62]
  • Unique markers found in DNA recovered from an Alaskan tooth were found in specific coastal tribes, and were rare in any of the other indigenous peoples in the Americas. This finding lends substantial credence to a migration theory that at least one set of early peoples moved south along the west coast of the Americas in boats.[63]
9,000–8,000 years ago:
  • Remains, known as Kennewick Man, are found in 1996 on the Columbia River near Kennewick, Washington. A skull and more than 300 bones and bone fragments were found at the site, making up among the oldest, best preserved, and most complete human remains ever found in North America. Initial radiocarbon dating indicated the remains were between 7,000 and 9,500 years old.[64] A leaf-shaped projectile found on the body was long, broad and had serrated edges, all fitting the definition of a Cascade point. This type of point is a feature of the Cascade phase, occurring in the archaeological record from roughly 6,000 to over 8,500 years ago.
  • 1930s-1990s no major Central American archaeological sites that go back more than 9,000 years have been found. Isolated finds of stone tools in Belize, Nicaragua and Costa Rica indicate that such sites almost certainly exist. Lack of funding for exploration in the areas has postponed likely finds.[61]
  • Tehuacan Valley of Mexico – people are living in rock shelters and using stone cooking pots, which were left in the center of the hearth. Maize was cultivated to be used in the same valley between 7,000–6,000 years ago.[65]

參見[编辑]

参考文献[编辑]

  1. ^ Goebel, Ted; Waters, Michael R.; O'Rourke, Dennis H. The Late Pleistocene dispersal of modern humans in the Americas (PDF). Science. 2008, 319 (5869): 1497–1502 [2010-02-05]. doi:10.1126/science.1153569. PMID 18339930. 
  2. ^ Gremillion, David H. Archaeolog: Pre Siberian Human Migration to America: Possible validation by HTLV-1 mutation analysis. Traumwerk.stanford.edu. 2008-09-25 [2010-10-12]. doi:10.1371/journal.pgen.1000078. 
  3. ^ Bonatto, Sandro L.; Salzano, Francisco M. A single and early migration for the peopling of the Americas supported by mitochondrial DNA sequence data. Proceedings of the National Academy of Sciences. 1997, 94: 1866–1871. doi:10.1073/pnas.94.5.1866. PMC 20009. PMID 9050871. 
  4. ^ Phillip M. White. American Indian chronology: chronologies of the American mosaic. Greenwood Publishing Group. 2006. 1 [29 November 2011]. ISBN 978-0-313-33820-5. 
  5. ^ 5.0 5.1 5.2 5.3 5.4 5.5 Wells, Spencer; Read, Mark. The Journey of Man - A Genetic Odyssey (Digitised online by Google books). Random House. 2002: 138–140 [2009-11-21]. ISBN 0-8129-7146-9. 
  6. ^ Chaw joins poop in archaeology arsenal. University of Wisconsin. 
  7. ^ Axelrod, Alan. The Complete Idiot's Guide to American History. Alpha Books. 2003 [2010-02-05]. ISBN 0-02-864464-6. 
  8. ^ Introduction. Government of Canada. Parks Canada. 2009 [2010-01-09]. "Canada's oldest known home is a cave in Yukon occupied not 12,000 years ago like the U.S. sites, but at least 20,000 years ago" 
  9. ^ Pleistocene Archaeology of the Old Crow Flats. Vuntut National Park of Canada. 2008 [2010-01-10]. "However, despite the lack of this conclusive and widespread evidence, there are suggestions of human occupation in the northern Yukon about 24,000 years ago, and hints of the presence of humans in the Old Crow Basin as far back as about 40,000 years ago." [失效連結]
  10. ^ 10.0 10.1 Atlas of the Human Journey. National Genographic. 
  11. ^ 11.0 11.1 11.2 11.3 First Americans. Southern Methodist University-David J. Meltzer, B.A., M.A., Ph.D. (原始内容存档于2009-11-01). 
  12. ^ 12.0 12.1 12.2 Jorney of mankind. Brad Shaw Foundation. 
  13. ^ Lister, Adrian; Bahn, Paul G. Mammoths: Giants of the Ice Age. By Adrian Lister, Paul G. Bahn. 2007-11-10. ISBN 978-0-7112-2801-6. 
  14. ^ Jody Hey, "On the Number of New World Founders: A Population Genetic Portrait of the Peopling of the Americas", Public Library of Science Biology, 3(6):e193 (2005)
  15. ^ 15.0 15.1 15.2 Beringian Standstill and Spread of Native American Founders. PLoS ONE (eISSN-1932-6203). 
  16. ^ 16.0 16.1 16.2 Than, Ker. New World Settlers Took 20,000-Year Pit Stop. National Geographic Society. 2008 [2010-01-23]. 
  17. ^ 17.0 17.1 The peopling of the Americas: Genetic ancestry influences health. Scientific American. 
  18. ^ First Americans Endured 20,000-Year Layover - Jennifer Viegas, Discovery News. [2009-10-05]. 
  19. ^ (2003) "Y-Chromosome Evidence for Differing Ancient Demographic Histories in the Americas," (pdf) Maria-Catira Bortolini, Francisco M. Salzano, Mark G. Thomas, Steven Stuart, Selja P. K. Nasanen, Claiton H. D. Bau, Mara H. Hutz, Zulay Layrisse, Maria L. Petzl-Erler, Luiza T. Tsuneto, Kim Hill, Ana M. Hurtado, Dinorah Castro-de-Guerra, Maria M. Torres, Helena Groot, Roman Michalski, Pagbajabyn Nymadawa, Gabriel Bedoya, Neil Bradman, Damian Labuda, Andres Ruiz-Linares. Department of Biology, University College, London; Departamento de Genética, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil; Instituto Venezolano de Investigaciones Científicas, Caracas, Venezuela; Departamento de Genética, Universidade Federal do Paraná, Curitiba, Brazil; 5Department of Anthropology, University of New Mexico, Albuquerque; 6Laboratorio de Genética Humana, Universidad de los Andes, Bogotá; Victoria Hospital, Prince Albert, Canada; Subassembly of Medical Sciences, Mongolian Academy of Sciences, Ulaanbaatar, Mongolia; Laboratorio de Genética Molecular, Facultad de Medicina, Universidad de Antioquia, Medellín, Colombia; Université de Montréal, Montreal. 73:524-539. Retrieved 2010-01-22.
  20. ^ Dyke, A.S., A. Moore, and L. Robertson, 2003, Deglaciation of North America, Geological Survey of Canada Open File, 1574. (Thirty-two digital maps at 1:7,000,000 scale with accompanying digital chronological database and one poster (two sheets) with full map series.)
  21. ^ 21.0 21.1 First Americans Endured 20,000-Year Layover - Jennifer Viegas, Discovery News. [2009-11-18]. "Archaeological evidence, in fact, recognizes that people started to leave Beringia for the New World around 40,000 years ago, but rapid expansion into North America didn't occur until about 15,000 years ago, when the ice had literally broken"  page 2
  22. ^ Charles C. Mann, 1491: new revelations of the Americas before Columbus, Random House Digital. 2006:  143, ISBN 978-1-4000-3205-1 
  23. ^ Jordan, David K. Prehistoric Beringia. University of California-San Diego. 2009 [2010-04-15]. 
  24. ^ Bronowski, Jacob. The Ascent of Man. British Broadcasting Corporation. 1975: 92–94. ISBN 0-563-10498-8.  已忽略文本“I can see no sensible way of interpreting that but to believe that a first migration of a small, related kinship group (all of blood group O) came into America, multiplied, and spread right to the South. Then a second migration, again of small groups, this time containing either A alone or both A and O, followed them only as far as North America.” (帮助)
  25. ^ 25.0 25.1 Learn about Y-DNA Haplogroup Q. Genebase Tutorials (Verbal tutorial possible). Genebase Systems. 2008. 
  26. ^ Orgel L. Prebiotic chemistry and the origin of the RNA world (PDF). Crit Rev Biochem Mol Biol. 2004, 39 (2): 99–123 [2010-01-19]. doi:10.1080/10409230490460765. PMID 15217990. 
  27. ^ Summary of knowledge on the subclades of Haplogroup Q. Genebase Systems. 2009 [2009-11-22]. 
  28. ^ 28.0 28.1 Ruhlen M. The origin of the Na-Dene. Proceedings of the National Academy of Sciences of the United States of America. 1998.November, 95 (23): 13994–6. doi:10.1073/pnas.95.23.13994. PMC 25007. PMID 9811914. 
  29. ^ Zegura SL, Karafet TM, Zhivotovsky LA, Hammer MF. High-resolution SNPs and microsatellite haplotypes point to a single, recent entry of Native American Y chromosomes into the Americas. Molecular Biology and Evolution. 2004.January, 21 (1): 164–75. doi:10.1093/molbev/msh009. PMID 14595095. 
  30. ^ mtDNA Variation among Greenland Eskimos. The Edge of the Beringian Expansion. Laboratory of Biological Anthropology, Institute of Forensic Medicine, University of Copenhagen, Copenhagen, McDonald Institute for Archaeological Research,University of Cambridge, Cambridge, University of Hamburg, Hamburg. 2000 [2009-11-22]. doi:10.1086/303038. 
  31. ^ The peopling of the New World - Perspectives from Molecular Anthropology. Department of Anthropology, University of Pennsylvania (Annual Review of Anthropology). 2004: Vol. 33, 551–583 [2010-02-03]. doi:10.1146/annurev.anthro.33.070203.143932. 
  32. ^ Native American Mitochondrial DNA Analysis Indicates That the Amerind and the Nadene Populations Were Founded by Two Independent Migrations. Center for Genetics and Molecular Medicine and Departments of Biochemistry and Anthropology, Emory University School of Medicine, Atlanta, Georgia. Genetics Society of America. Vol 130, 153-162. [2009-11-28]. 
  33. ^ Marder, William. Indians in the Americas: the untold story. By William Marder. 2005-04. ISBN 978-1-58509-104-1. 
  34. ^ Norman Herz; Ervan G. Garrison. Geological methods for archaeology. Oxford University Press. 1998. 125 [29 November 2011]. ISBN 978-0-19-509024-6. 
  35. ^ Palaeo-Indian archaeology. Canadian Studies Program, Canadian Heritage. 
  36. ^ 36.0 36.1 The Topper Site in South Carolina. Ohio Archaeological Inventor. 
  37. ^ Gibbon, Guy E; Ames, Kenneth M. Archaeology of Prehistoric Native America: An Encyclopedia. By Guy E. Gibbon, Kenneth M. Ames (1998). 1998. ISBN 978-0-8153-0725-9. 
  38. ^ Dickason, Olive. Canada's First Nations: A History of the Founding Peoples from the Earliest Times. 2nd edition. Toronto: Oxford University Press, 1997.
  39. ^ Alberta History pre 1800 - Jasper Alberta. AlbertaJasper.com. 
  40. ^ pre glaciology in Alberta. Calgary university. 
  41. ^ An mtDNA view of the peopling of the world by Homo sapiens. Cambridge DNA Services. 2007 [2011-06-01]. 
  42. ^ Richmond, G.M., Fullerton, D.S. Summation of Quaternary glaciations in the United States of America. Quaternary Science Reviews. 1986, 5: 183–196. doi:10.1016/0277-3791(86)90184-8. 
  43. ^ Tamm E, Kivisild T, Reidla M, et al.. Beringian Standstill and Spread of Native American Founders. PLoS ONE. 2007, 2 (9): e829. doi:10.1371/journal.pone.0000829. PMC 1952074. PMID 17786201. 
  44. ^ 44.0 44.1 Beginnings to 1500 C.E.. Encyclopedia of Canada's Peoples. 
  45. ^ Fagundes, Nelson J.R.; Ricardo Kanitz, Roberta Eckert, Ana C.S. Valls, Mauricio R. Bogo, Francisco M. Salzano, David Glenn Smith, Wilson A. Silva, Marco A. Zago, Andrea K. Ribeiro-dos-Santos, Sidney E.B. Santos, Maria Luiza Petzl-Erler, and Sandro L. Bonatto. Mitochondrial Population Genomics Supports a Single Pre-Clovis Origin with a Coastal Route for the Peopling of the Americas. American Journal of Human Genetics. 2008, 82 (3): 583–592. doi:10.1016/j.ajhg.2007.11.013. PMC 2427228. PMID 18313026. 
  46. ^ Vertebrate paleontology and the alleged ice-free corridor: The meat of the matter. ScienceDirect a registered trademark of Elsevier B.V. 
  47. ^ # Martin, Paul S. (2005): Twilight of the mammoths: Ice Age extinctions and the rewilding of America. University of California Press, Berkeley. ISBN 0-520-23141-4
  48. ^ Fiedal, Stuart. Sudden Deaths: The Chronology of Terminal Pleistocene Megafaunal Extinction//In Haynes, Gary. American Megafaunal Extinctions at the End of the Pleistocene. Springer. 2009: 21–37. doi:10.1007/978-1-4020-8793-6_2. ISBN 978-1-4020-8792-9. 
  49. ^ Meadowcroft Rockshelter, Pennsylvania.. Bradshaw Foundation. 
  50. ^ 50.0 50.1 Chilean Field Yields New Clues to Peopling of Americas. The New York Times. By John Noble Wilford. 
  51. ^ Cactus Hill Update. Archaeological Institute of America. 
  52. ^ Taimataima site. Dr. José R. Oliver. 
  53. ^ Connor, Steve. Does skull prove that the first Americans came from Europe?. The Independent (London). 3 December 2002 [23 June 2011]. 
  54. ^ George Weber. Tibito and El Abra sites (Colombia ). The Andaman Association. 
  55. ^ 55.0 55.1 Evidence Supports Earlier Date for People in North America. New York Times. 2008-04-04 [2010-05-13]. 
  56. ^ Worldwide glacier retreat. RealClimate. 
  57. ^ First Americans. National Geographic society. 
  58. ^ Jaguay and Tacahuay sites (Arequipa and Tacna, Peru). Vantage World Travel. 
  59. ^ Early North American Cultures. Minnesota State University. 
  60. ^ Debert Palaeo-Indian Site. Nova Scotia Museum. 
  61. ^ 61.0 61.1 61.2 Lagoa Santa sites (Minas Gerais, Brazil). Andaman Association. 
  62. ^ Oldest North American Mummy. Archaeological Institute of America. 
  63. ^ On Your Knees Cave. Timothy H. Heaton. The University of South Dakota. 2002 [2009-11-21]. "The American Journal of Physical Anthropolog reports new DNA-based research that links the DNA retrieved from a 10,000-year-old fossilized tooth from an Alaskan island, with specific coastal tribes in Tierra del Fuego, Ecuador, Mexico and California. Unique markers found in DNA recovered from the Alaskan tooth were found in these specific coastal tribes, and were rare in any of the other indigenous peoples in the Americas. This finding lends substantial credence to a migration theory that at least one set of early peoples moved south along the west coast of the Americas in boats. A previous study showed that mtDNA (human mitochondrial DNA) from indigenous populations in coastal British Columbia showed similarities to coastal populations in Southern California, while inland populations in both localities differed markedly. Dates of 9,730 and 9,880 years BP were obtained on the human remains, making them the oldest ever found in Alaska or Canada. The associated bone tool was dated to 10,300 years old" 
  64. ^ Custred, Glynn. The Forbidden Discovery of Kennewick Man. Academic Questions. 2000, 13 (3): 12–30. doi:10.1007/s12129-000-1034-8. 
  65. ^ America: 8000 to 5000 B.C.. Rice University.