DNA & Native American origins

Wall Street Journal
10 september 1993 p 1, col. 1

Strands of Time

A Geneticist's Work On DNA Bears Fruit For Anthropologists
Variations in Fragments Hint Some American Natives May Hail From Polynesia
The Controversy
Over Eve

by Jerry E. Bishop
staff reporter

St. Louis -- Douglas C. Wallace can see the future in a tiny strand of DNA. ... But he also can peer deep into the past. He has looked back more than 100,000 years to the first humans in Africa. And recently, as a gathering here of science reporters, he painted a picture of prehistoric migrations emerging from DNA that is exciting anthropologists.

The scene depicts groups of prehistoric, intrepid mariners moving, not out of Siberia as anthropologists have long assumed, but out of Southeast Asia across the Pacific into the Americas 6,000 to 12,000 years ago. If this picture is accurate, it makes many American Indians distant cousins of the Polynesians.

Dr. Wallace's crystal ball is a unique fragment of DNA hidden in every human cell. This clairvoyant DNA is distinct and separate from the long strings of DNA that house almost all human genes in the cell nucleus. It resides, instead, in an outlying compartment called a mitochondrion. Hence its name: mitochondrial DNA, or simply mtDNA.

The mtDNA contains a mere 37 genes compared with the 50,000 to 100,000 genes in nuclear DNA. And these few mtDNA genes are devoted largely to the mitochondria's principal job of producing chemical energy for the thousands of second-by-second chemical reactions in a cell.

Yet, astonished medical researchers are finding that defects in this snippet of DNA can cause human disease. And, to the surprise of anthropologists, mtDNA is turning into a kind of biological Rosetta stone for decoding human origins.

Loud Ties, Deep Theories

Few scientists studying mtDNA are probing deeper--and risking more--than Doug Wallace, a professor of genetics and molecular medicine at Emory University in Atlanta. Slight and bespectacled, the 47-year-old scientist is famous among his students for loud neckties and, until recently, his polyester suits. ("When I finally got a raise my wife took all my leisure jackets and threw them away," he says.)

Clearly, mtDNA has become Dr. Wallace's consuming, almost obsessive interest. ... Yet this detour into anthropology via mtDNA isn't without controversy.

Dr. Wallace, for example, subscribes to the much-publicized "Eve hypothesis," in which a reading of mtDNA indicates modern humans originated in Africa 100,000 to 200,000 years ago. Some anthropologists retort that mtDNA is an unreliable clock for timing human evolution, and that the fossil evidence shows modern humans evolved much earlier than mtDNA indicates.

But it is another strange property of mitochondria that unexpectedly thrust the young scientist into the study of human origins. Humans inherit two copies of the nuclear genes, one from each parent. But only the mother's mitochondrial genes are passed on to the child for reasons still not fully understood.

Thus, every person's mtDNA is descended in a direct line through female ancestors. There isn't any DNA from the father's side of the family mixed in to confuse the line of descent. This phenomenon of maternal inheritance had been seen in animals but it was a young Doug Wallace who showed it occurred in humans in a series of experiments in 1979 at Stanford University in Palo Alto, Calif.

Dr. Wallace ... saw in this maternal inheritance a way to tell how closely groups of people are related. As mtDNA is passed down from mother to daughter, innocuous alterations or mutations are bound to occur. Over a few thousand years, groups of people who live together and intermarry will accumulate distinctive patterns of these mutations.

Continental Divide

In 1981 Dr. Wallace headed a Stanford research team that found that ethnic groups could be identified and linked to their continent of origin by the mutation patterns in their mtDNA. Moreover, by determining how often these telltale mutations occurred, it was possible to calculate how long ago certain groups stopped intermarrying and separated, each going off to develop its own unique pattern of mtDNA mutations.

"Each continent had a different pattern" of mtDNA mutations, Dr. Wallace recalls of his research findings. Africans had mtDNA variations that distinguished them from Asians who, in turn, had variations that distinguished them from European-American Caucasians. "That's when I knew we had an anthropological story," he says. ...

Dr. Wallace began studying the mtDNA of Native Americans in the mid-1980s in hopes of resolving a long-raging debate over when prehistoric peoples entered the Americas. The presumption long has been that the ancestors of Native Americans came from Siberia. But anthropologists have argued for year over how many, and when, such migrations occurred.

The mtDNA analyses are showing that the ancestors of the Amerinds, who comprise most Native Americans, entered the Americans in a single migratory wave 20,000 to 40,000 years ago, Dr. Wallace and his Emory colleagues ... reported last year. This puts humans in the Americas long before a fluted stone-spear point--the oldest American tool ever found--was dropped by a prehistoric dweller near Clovis, N.M., 11,000 years ago.

The researchers also found that ancestors of the Navajo, Apache and other members of a Native American group, known collectively as the Na-Dene, are latecomers; they entered the continent in a second migration a mere 5,000 to 10,000 years ago, the research indicates.

Polynesian Links?

To their surprise, however, the researchers found that native Siberians lack one peculiar mutation that appeared in the Amerinds 6,000 to 10,000 years ago. This raises the question of where, if not from Siberia, this mtDNA originated.

It turns out, Dr. Wallace says, that this particular mutation pattern is also found in aboriginal populations in Southeast Asia and in the islands of Melanesia and Polynesia. This hints at what may have been "one of the most astounding migrations in human experience," he says. A group of ancient peoples moved out of China into Malaysia where they became sailors and populated the islands of the South Pacific.

Then some 6,000 to 12,000 years ago these ancient mariners made it to the Americas. "I don't know how they came," Dr. Wallace says. "They either came across the Pacific to Central and South America or they went up the east coast of Asia and across the northern Pacific to Alaska and Canada," he says. He already is examining mtDNA samples from natives of the Kamchatka Peninsula north of Japan to see if there is any mtDNA trace of these ancient sailors.

... (the article then goes into mitochondrial mutation and its affect/cause of aging.)

Sunday, March 9, 1997 Reuter

British teacher finds long-lost relative -- from 9,000 years ago

L O N D O N -- British scientists Saturday celebrated their feat in tracing a living descendant of a 9,000-year-old skeleton and establishing the world's oldest known family tree.

In an astonishing piece of detective work, they matched DNA material extracted from the tooth cavity of Britain's oldest complete skeleton with that of a 42-year-old history teacher.

The genetic material showed without doubt that teacher Adrian Targett is a direct descendant through his mother's line of the skeleton known as Cheddar Man -- found in 1903 in caves in Cheddar Gorge in southwest England.

The Oxford team took DNA swabs from about 20 local people whose families had lived in the Cheddar area for generations. Targett, who teaches modern history, said he took part only to make up the numbers.

"Appropriately enough, I am a history teacher, but I have to admit I know next to nothing about Cheddar Man. I suppose I really should try to include him in my family tree."


DNA used to trace relationship to ancestors
Subject: UK teacher adds Stone Age caveman to family tree
Organization: Copyright 1997 by Reuters
Date: Sat, 8 Mar 1997 12:51:11 PST

LONDON (Reuter) - British scientists Saturday celebrated their feat in tracing a living descendant of a 9,000-year-old skeleton and establishing the world's oldest known family tree.

In an astonishing piece of detective work, they matched DNA material extracted from the tooth cavity of Britain's oldest complete skeleton with that of a 42-year-old history teacher.

The genetic material showed without doubt that teacher Adrian Targett is a direct descendant through his mother's line of the skeleton known as Cheddar Man -- found in 1903 in caves in Cheddar Gorge in south-west England.

"It is extraordinary that the DNA survives at all but we were able to extract it and sequence it," said Bryan Sykes of Oxford University's Institute of Molecular Medicine.

"They would have shared a common ancestor about 10,000 years ago so they are related," Sykes added.

The results of the tests, carried out for a television program on archaelogy, were announced Friday and were published in Saturday newspapers.

Targett lives less than a mile from the caves where Cheddar Man was found. Previous tests have shown that Cheddar Man suffered a violent death at the age of about 23 in 7150 BC.

The Oxford University team spent months analyzing samples from the skeleton before taking DNA swabs from about 20 local people whose families had lived in the Cheddar area for generations.

Targett, who teaches modern history, said he took part only to make up the numbers.

"I was astonished when the scientists said I was the descendant. Appropriately enough I am a history teacher but I have to admit I know next to nothing about Cheddar Man. I suppose I really should try to include him in my family tree," he told reporters.

Targett can now boast a lineage centuries older than that of Britain's royal family which traces its heritage back to 829 AD.

The oldest previously recorded relative was the great-great great-great grandfather of Confucius, who lived in the 8th century BC.

Scientists said the odds on finding a match were not as enormous as might appear because of the relatively small number of people who lived in Britain's Stone Age.

Sykes said the discovery strengthened the theory that the ancestors of modern-day Britons were hunter-gatherers rather than farmers.

"There has been an idea that most modern European are decsended from farmers that came in from the Middle East about 10,000 years ago, reaching Britain about 6,000 years ago.

"This kind of evidence shows that is probably not true and that modern Britons are in fact descended from the earlier inhabitants like Cheddar Man who existed on hunting and gathering and who were not farmers," Sykes told BBC radio.

Scientists said they were now hoping to use the same DNA sampling technique to prove whether Neanderthal man, which died out about 25,000 years ago, was linked to homo-sapiens humans or was a completely different species.

Professor Chris Stringer, a researcher at the Natural History Museum, said: "This work may finally let us end a 150-year-old argument which has existed since a Neanderthal man fossil was first found."

Targett, an only child who has no children himself, was still coming to terms with the idea of having a caveman as a relative.

But his wife Catherine said; "Maybe this explains why he likes his steaks rare."


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SEARCH: pubmed FOR: wallace dc AND Emory


Am J Hum Genet 1998 Dec;63(6):1852-61

mtDNA haplogroup X: An ancient link between Europe/Western Asia and North America?

Brown MD, Hosseini SH, Torroni A, Bandelt HJ, Allen JC, Schurr TG, Scozzari R, Cruciani F, Wallace DC

Center for Molecular Medicine, Emory University School of Medicine, Atlanta, GA, USA. mdbrown@gmm.gen.emory.edu

On the basis of comprehensive RFLP analysis, it has been inferred that approximately 97% of Native American mtDNAs belong to one of four major founding mtDNA lineages, designated haplogroups "A"-"D." It has been proposed that a fifth mtDNA haplogroup (haplogroup X) represents a minor founding lineage in Native Americans. Unlike haplogroups A-D, haplogroup X is also found at low frequencies in modern European populations. To investigate the origins, diversity, and continental relationships of this haplogroup, we performed mtDNA high-resolution RFLP and complete control region (CR) sequence analysis on 22 putative Native American haplogroup X and 14 putative European haplogroup X mtDNAs. The results identified a consensus haplogroup X motif that characterizes our European and Native American samples. Among Native Americans, haplogroup X appears to be essentially restricted to northern Amerindian groups, including the Ojibwa, the Nuu-Chah-Nulth, the Sioux, and the Yakima, although we also observed this haplogroup in the Na-Dene-speaking Navajo. Median network analysis indicated that European and Native American haplogroup X mtDNAs, although distinct, nevertheless are distantly related to each other. Time estimates for the arrival of X in North America are 12,000-36,000 years ago, depending on the number of assumed founders, thus supporting the conclusion that the peoples harboring haplogroup X were among the original founders of Native American populations. To date, haplogroup X has not been unambiguously identified in Asia, raising the possibility that some Native American founders were of Caucasian ancestry.

PMID: 9837837


Hum Genet 1997 Oct;100(5-6):536-43

Y chromosome polymorphisms in native American and Siberian populations: identification of native American Y chromosome haplotypes.

Lell JT, Brown MD, Schurr TG, Sukernik RI, Starikovskaya YB, Torroni A, Moore LG, Troup GM, Wallace DC

Center for Molecular Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA.

We have initiated a study of ancient male migrations from Siberia to the Americas using Y chromosome polymorphisms. The first polymorphism examined, a C-->T transition at nucleotide position 181 of the DYS199 locus, was previously reported only in Native American populations. To investigate the origin of this DYS199 polymorphism, we screened Y chromosomes from a number of Siberian, Asian, and Native American populations for this and other markers. This survey detected the T allele in all five Native American populations studied at an average frequency of 61%, and in two of nine native Siberian populations, the Siberian Eskimo (21%) and the Chukchi (17%). This finding suggested that the DYS199 T allele may have originated in Beringia and was then spread throughout the New World by the founding populations of the major subgroups of modern Native Americans. We further characterized Native American Y chromosome variation by analyzing two additional Y chromosome polymorphisms, the DYS287 Y Alu polymorphic (YAP) element insertion and a YAP-associated A-->G transition at DYS271, both commonly found in Africans. We found neither African allele associated with the DYS199 T allele in any of the Native American or native Siberian populations. However, we did find DYS287 YAP+ individuals who harbored the DYS199 C allele in one Native American population, the Mixe, and in one Asian group, the Tibetans. A correlation of these Y chromosome alleles in Native Americans with those of the DYS1 locus, as detected by the p49a/p49f (p49a,f) probes on TaqI-digested genomic DNA, revealed a complete association of DYS1 alleles (p49a,f haplotypes) 13, 18, 66, 67 and 69 with the DYS199 T allele, while DYS1 alleles 8 and 63 were associated with both the DYS199 C and T allele.

PMID: 9341867


Eur J Hum Genet 1997 Jan-Feb;5(1):25-34

Mitochondrial DNA and Y chromosome-specific polymorphisms in the Seminole Tribe of Florida.

Huoponen K, Torroni A, Wickman PR, Sellitto D, Gurley DS, Scozzari R, Wallace DC

Department of Genetics and Molecular Medicine, Emory University School of Medicine, Atlanta, Ga. 30322, USA.

Mitochondrial DNA (mtDNA) sequence variation was examined in 37 Seminoles from Florida by polymerase chain reaction amplification and high resolution restriction endonuclease analysis. The Y chromosome TaqI restriction fragment length polymorphisms detected by the probes 49a, 49f, and 12f2 were examined in the 26 males of this group. Analysis of the mtDNA revealed that all four Native American haplogroups (A, B, C and D) were present in the Seminoles encompassing about 95% of the Seminole mtDNAs. No European mtDNAs were found among the Seminoles, but two mtDNAs (about 5%) were members of the African-specific haplogroup L1, thus indicating that a limited number of African women were incorporated in the Seminole tribe. Analysis of Y chromosome haplotypes supports the hypothesis that haplotypes 18 and 63 are the most likely founding Native American Y chromosome haplotypes from Asia. However, 11% of the Seminole Y chromosomes represented haplotypes generally attributed to Europeans, though none harbored standard African haplotypes. These findings support historical evidence that the Seminole tribe has integrated individuals of European and African ancestry, but suggests that the sex ratio of nonnatives from different continents may have varied.

PMID: 9156318


Am J Hum Genet 1995 Jul;57(1):133-49

Analysis of mtDNA variation in African populations reveals the most ancient of all human continent-specific haplogroups.

Chen YS, Torroni A, Excoffier L, Santachiara-Benerecetti AS, Wallace DC

Department of Genetics and Molecular Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA.

mtDNA sequence variation was examined in 140 Africans, including Pygmies from Zaire and Central African Republic (C.A.R.) and Mandenkalu, Wolof, and Pular from Senegal. More than 76% of the African mtDNAs (100% of the Pygmies and 67.3% of the Senegalese) formed one major mtDNA cluster (haplogroup L) defined by an African-specific HpaI site gain at nucleotide pair (np) 3592. Additional mutations subdivided haplogroup L into two subhaplogroups, each encompassing both Pygmy and Senegalese mtDNAs. A novel 12-bp homoplasmic insertion in the intergenic region between tRNA(Tyr) and cytochrome oxidase I (COI) genes was also observed in 17.6% of the Pygmies from C.A.R. This insertion is one of the largest observed in human mtDNAs. Another 25% of the Pygmy mtDNAs harbored a 9-bp deletion between the cytochrome oxidase II (COII) and tRNA(Lys) genes, a length polymorphism previously reported in non-African populations. In addition to haplogroup L, other haplogroups were observed in the Senegalese. These haplogroups were more similar to those observed in Europeans and Asians than to haplogroup L mtDNAs, suggesting that the African mtDNAs without the HpaI np 3592 site could be the ancestral types from which European and Asian mtDNAs were derived. Comparison of the intrapopulation sequence divergence in African and non-African populations confirms that African populations exhibit the largest extent of mtDNA variation, a result that further supports the hypothesis that Africans represent the most ancient human group and that all modern humans have a common and recent African origin. The age of the total African variation was estimated to be 101,000-133,000 years before present (YBP), while the age of haplogroup L was estimated at 98,000-130,000 YBP. These values substantially exceed the ages of all Asian- and European-specific mtDNA haplogroups.

PMID: 7611282


Hum Mutat 1995;5(4):310-7

African, Native American, and European mitochondrial DNAs in Cubans from Pinar del Rio Province and implications for the recent epidemic neuropathy in Cuba. Cuba Neuropathy Field Investigation Team.

Torroni A, Brown MD, Lott MT, Newman NJ, Wallace DC

Department of Genetics, Emory University School of Medicine, Atlanta, Georgia 30332, USA.

Genetic predisposition, particularly specific mitochondrial DNA (mtDNA) backgrounds, has been proposed as a contributing factor in the expression of an epidemic of bilateral optic neuropathy that has affected residents of Cuba since 1991. To substantiate or refute the possibility that specific subsets of mtDNAs could participate in disease expression, we took advantage of the heterogeneous ethnic origin of the Cuban population and the recent identification of a number of mtDNA polymorphisms that appear to be specific for Africans, Native Americans, and Europeans. The screening of both carefully selected people with epidemic neuropathy and control subjects from the Pinar del Rio Province for these polymorphisms revealed that African, Native American, and European mtDNA haplotypes were equally represented among case and control subjects, and suggested that approximately 50% of Cuban mtDNAs originated from Europeans, 46% from Africans, and 4% from Native Americans. These findings demonstrate that mutations arising in specific mtDNAs are unlikely to play a role in the epidemic neuropathy and indicate that analysis of mtDNA haplotypes can be a valuable tool for assessing the relative maternal contribution of Africans, Native Americans, and Europeans in a mixed population.

PMID: 7627185


Am J Hum Genet 1994 Feb;54(2):303-18

mtDNA and Y-chromosome polymorphisms in four Native American populations from southern Mexico.

Torroni A, Chen YS, Semino O, Santachiara-Beneceretti AS, Scott CR, Lott MT, Winter M, Wallace DC

Department of Genetics and Molecular Medicine, Emory University School of Medicine, Atlanta, Georgia 30322.

mtDNA sequence variation was examined in 60 Native Americans (Mixtecs from the Alta, Mixtecs from the Baja, Valley Zapotecs, and Highland Mixe) from southern Mexico by PCR amplification and high-resolution restriction endonuclease analysis. Four groups of mtDNA haplotypes (haplogroups A, B, C, and D) characterize Amerind populations, but only three (haplogroups A, B, and C) were observed in these Mexican populations. The comparison of their mtDNA variation with that observed in other populations from Mexico and Central America permits a clear distinction among the different Middle American tribes and raises questions about some of their linguistic affiliations. The males of these population samples were also analyzed for Y-chromosome RFLPs with the probes 49a, 49f, and 12f2. This analysis suggests that certain Y-chromosome haplotypes were brought from Asia during the colonization of the Americas, and a differential gene flow was introduced into Native American populations from European males and females.

Comment in: Am J Hum Genet. 1995 May;56(5):1234-8

PMID: 8304347


Proc Natl Acad Sci U S A 1994 Feb 1;91(3):1158-62

Mitochondrial DNA "clock" for the Amerinds and its implications for timing their entry into North America.

Torroni A, Neel JV, Barrantes R, Schurr TG, Wallace DC

Department of Genetics and Molecular Medicine, Emory University, Atlanta, GA 30322.

Students of the time of entry of the ancestors of the Amerinds into the New World are divided into two camps, one favoring an "early" entry [more than approximately 30,000 years before the present (YBP)], the other favoring a "late" entry (less than approximately 13,000 YBP). An "intermediate" date is unlikely for geological reasons. The correlation of the appropriate data on mtDNA variation in Amerinds with linguistic, archaeological, and genetic data offers the possibility of establishing a time frame for mtDNA evolution in Amerinds. In this paper, we estimate that the separation of the Chibcha-speaking tribes of Central America from other linguistic groups/nascent tribes began approximately 8000-10,000 YBP. Characterization of the mtDNA of 110 Chibcha speakers with 14 restriction enzymes leads on the basis of their time depth to an estimated mtDNA nucleotide substitution rate for Amerinds of 0.022-0.029% per 10,000 years. As a first application of this rate, we consider the mtDNA variation observed in 18 Amerind tribes widely dispersed throughout the Americas and studied by ourselves with the same techniques, and we estimate that if the Amerinds entered the New World as a single group, that entry occurred approximately 22,000-29,000 YBP. This estimate carries a large but indeterminate error. The mtDNA data are thus at present equivocal with respect to the most likely times of entry of the Amerind into the New World mentioned above but favor the "early" entry hypothesis.

PMID: 8302846


Am J Hum Genet 1993 Sep;53(3):591-608

mtDNA variation of aboriginal Siberians reveals distinct genetic affinities with Native Americans.

Torroni A, Sukernik RI, Schurr TG, Starikorskaya YB, Cabell MF, Crawford MH, Comuzzie AG, Wallace DC

Department of Genetics and Molecular Medicine, Emory University, Atlanta, GA 30322.

The mtDNA variation of 411 individuals from 10 aboriginal Siberian populations was analyzed in an effort to delineate the relationships between Siberian and Native American populations. All mtDNAs were characterized by PCR amplification and restriction analysis, and a subset of them was characterized by control region sequencing. The resulting data were then compiled with previous mtDNA data from Native Americans and Asians and were used for phylogenetic analyses and sequence divergence estimations. Aboriginal Siberian populations exhibited mtDNAs from three (A, C, and D) of the four haplogroups observed in Native Americans. However, none of the Siberian populations showed mtDNAs from the fourth haplogroup, group B. The presence of group B deletion haplotypes in East Asian and Native American populations but their absence in Siberians raises the possibility that haplogroup B could represent a migratory event distinct from the one(s) which brought group A, C, and D mtDNAs to the Americas. Our findings support the hypothesis that the first humans to move from Siberia to the Americas carried with them a limited number of founding mtDNAs and that the initial migration occurred between 17,000-34,000 years before present.

PMID: 7688933


Am J Hum Genet 1993 Sep;53(3):563-90

Asian affinities and continental radiation of the four founding Native American mtDNAs.

Torroni A, Schurr TG, Cabell MF, Brown MD, Neel JV, Larsen M, Smith DG, Vullo CM, Wallace DC

Department of Genetics and Molecular Medicine, Emory University, Atlanta, GA 30322.

The mtDNA variation of 321 individuals from 17 Native American populations was examined by high-resolution restriction endonuclease analysis. All mtDNAs were amplified from a variety of sources by using PCR. The mtDNA of a subset of 38 of these individuals was also analyzed by D-loop sequencing. The resulting data were combined with previous mtDNA data from five other Native American tribes, as well as with data from a variety of Asian populations, and were used to deduce the phylogenetic relationships between mtDNAs and to estimate sequence divergences. This analysis revealed the presence of four haplotype groups (haplogroups A, B, C, and D) in the Amerind, but only one haplogroup (A) in the Na-Dene, and confirmed the independent origins of the Amerinds and the Na-Dene. Further, each haplogroup appeared to have been founded by a single mtDNA haplotype, a result which is consistent with a hypothesized founder effect. Most of the variation within haplogroups was tribal specific, that is, it occurred as tribal private polymorphisms. These observations suggest that the process of tribalization began early in the history of the Amerinds, with relatively little intertribal genetic exchange occurring subsequently. The sequencing of 341 nucleotides in the mtDNA D-loop revealed that the D-loop sequence variation correlated strongly with the four haplogroups defined by restriction analysis, and it indicated that the D-loop variation, like the haplotype variation, arose predominantly after the migration of the ancestral Amerinds across the Bering land bridge.

Comment in: Am J Hum Genet. 1994 Aug;55(2):413-4 Am J Hum Genet. 1995 May;56(5):1234-8

PMID: 7688932


Hum Biol 1992 Jun;64(3):403-16

American Indian prehistory as written in the mitochondrial DNA: a review.

Wallace DC, Torroni A

Center for Genetics and Molecular Medicine, Emory University, Atlanta, GA 30322.

Native Americans have been divided into three linguistic groups: the reasonably well-defined Eskaleut and Nadene of northern North America and the highly heterogeneous Amerind of North, Central, and South America. The heterogeneity of the Amerinds has been proposed to be the result of either multiple independent migrations or a single ancient migration with extensive in situ radiation. To investigate the origin and interrelationship of the American Indians, we examined the mitochondrial DNA (mtDNA) variation in 87 Amerinds (Pima, Maya, and Ticuna of North, Central, and South America, respectively), 80 Nadene (Dogrib and Tlingit of northwest North America and Navajo of the southwest North America), and 153 Asians from 7 diverse populations. American Indian mtDNAs were found to be directly descended from five founding Asian mtDNAs and to cluster into four lineages, each characterized by a different rare Asian mtDNA marker. Lineage A is defined by a HaeIII site gain at np 663, lineage B by a 9-bp deletion between the COII and tRNA(Lys) genes, lineage C by a HincII site loss at np 13259, and lineage D by an AluI site loss at np 5176. The North, Central, and South America Amerinds were found to harbor all four lineages, demonstrating that the Amerinds originated from a common ancestral genetic stock. The genetic variation of three of the four Amerind lineages (A, C, and D) was similar with a mean value of 0.084%, whereas the sequence variation in the fourth lineage (B) was much lower, raising the possibility of an independent arrival. By contrast, the Nadene mtDNAs were predominantly from lineage A, with 27% of them having a Nadene-specific RsaI site loss at np 16329. The accumulated Nadene variation was only 0.021%. These results demonstrate that the Amerind mtDNAs arose from one or maybe two Asian migrations that were distinct from the migration of the Nadene and that the Amerind populations are about four times older than the Nadene.

Publication Types: Historical article

Comment in: Hum Biol. 1992 Jun;64(3):271-9

PMID: 1351474


Am J Hum Genet 1990 Mar;46(3):613-23

Amerindian mitochondrial DNAs have rare Asian mutations at high frequencies, suggesting they derived from four primary maternal lineages.

Schurr TG, Ballinger SW, Gan YY, Hodge JA, Merriwether DA, Lawrence DN, Knowler WC, Weiss KM, Wallace DC

Department of Biochemistry, Emory University School of Medicine, Atlanta, GA.

The mitochondrial DNA (mtDNA) sequence variation of the South American Ticuna, the Central American Maya, and the North American Pima was analyzed by restriction-endonuclease digestion and oligonucleotide hybridization. The analysis revealed that Amerindian populations have high frequencies of mtDNAs containing the rare Asian RFLP HincII morph 6, a rare HaeIII site gain, and a unique AluI site gain. In addition, the Asian-specific deletion between the cytochrome c oxidase subunit II (COII) and tRNA(Lys) genes was also prevalent in both the Pima and the Maya. These data suggest that Amerindian mtDNAs derived from at least four primary maternal lineages, that new tribal-specific variants accumulated as these mtDNAs became distributed throughout the Americas, and that some genetic variation may have been lost when the progenitors of the Ticuna separated from the North and Central American populations.

PMID: 1968708


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