There have been several models of migration to the New
(Human migration into the Americas) proposed by
various academic communities. The question of how, when and why
) first entered
is of intense interest to
, and has been a subject of
heated debate for centuries. Current understanding of human
migration into the Americas derives from advances in four
integrated disciplines: archeology
There is general agreement that America was first settled from Asia
by people who migrated across Beringia
pattern of migration, its timing, and the place of origin in Asia
of the peoples that migrated to the Americas remains unclear. In
recent years researchers have enroll familiar tools to validate or
reject what have become more or less entrenched theories like
. As new discoveries come
to light, past hypotheses are reevaluated and new theories
constructed. The archeological evidence suggest that Paleo-Indians
first "widespread" habitation of the Americas occurred during the
end of the last glacial period
or more specifically what is known as the late glacial maximum
, around 16,500 -
13,000 years ago.
Understanding the debate
Time line of important events
associated with Paleoindians
The chronology of migration models is currently divided into two
general approaches. The first is the short chronology
with the first movement beyond Alaska into the New
World occurring no earlier than 15,000 – 17,000 years ago, followed
by successive waves of immigrants. The second belief is the
long chronology theory,
which proposes that the first
group of people entered the hemisphere at a much earlier date,
possibly 21,000 - 40,000 years ago, with a much later mass
secondary wave of immigrants.
One factor fueling the debate is the discontinuity of archaeological
evidence between North
Paleo-Indian sites. A roughly uniform techno-complex
pattern known as Clovis
appears in North and Central American
sites from at least 13,500
years ago onwards. South American sites of equal antiquity do not
share the same consistency and exhibit more diverse cultural
patterns. Thus, archaeologists conclude that the "Clovis-first",
and Paleo-Indian time frame do not adequately explain complex
tools appearing in South
America. Some theorists seek to develop a colonization model that
integrates both North and South American archaeological
studies concluded that the
"initial founders" of the Americas emerged from a single-source
ancestral population that evolved in isolation, likely in Beringia
. The isolation in Beringia might have
lasted 5,000 - 15,000 years. Age estimates based on Y-chromosome
micro-satellite place diversity of the American Y-chromosome Q-haplo
10,000 to 15,000 years ago. These dates are in relative agreement
with the age of well-established American archaeological sites
showing complete habitation of the continent.
Migrants from northeastern Asia could have walked to Alaska with
relative ease when Beringia was above sea level. But traveling
south from Alaska to the rest of North America may have posed
significant challenges. The two main possible routes proposed south
for human migration are: down the Pacific
or by way of an interior passage along the eastern flank
of the Rocky Mountains
. When the
and Cordilleran ice sheets
were at their
maximum extent, both routes were likely impassable. The Cordilleran
sheet reached across to the Pacific shore in the west, and its
eastern edge abutted the Laurentide, near the present border
between British Columbia and Alberta.Geological evidence suggests
the Pacific coastal route was open for overland travel before
23,000 years ago and after 15,000 years ago. During the coldest
millennia of the last ice age, roughly 23,000 to 19,000 years ago,
lobes of glaciers
hundreds of kilometers
wide flowed down to the sea. Deep crevasses scarred their surfaces,
making travel across them dangerous. Even if people traveled by
boat—a claim for which there is currently no direct archaeological
evidence as sea level rise has hidden the old coast line — the
journey would have been difficult with abundant icebergs
in the water. Around 15,000 to 13,000
years ago the coast was presumed ice-free. Additionally, by this
time the climate had warmed, and lands were covered in grass and
trees. Early Paleo-Indian
have readily replenished their food supplies, repaired clothing and
tents, and replaced broken or lost tools.
Coastal or watercraft
theories have broad implications,
one being that Paleo-Indians in North America may not have been
purely terrestrial "big-game hunters", but instead were already
adapted to maritime or semi-maritime lifestyles. Additionally, it
is possible that "Beringian" (western Alaskan) groups migrated into
the northern interior only to meet their demise during the last glacial maximum
20,000 years ago. Thus leavening evidence of occupation in certain
areas; however they would not be considered a founding population
, unless they had managed
to migrate south and populate before the coldest part of the
Timeline of archeological, geological and genetic evidence
|40,000 B.C. - 25,000 B.C.
- Bison (buffalo), mammoths, and mastodons are
thought to have migrated from Asia to America about this time. This
would imply a land bridge between the continents and would have
been a food supply.
|30,000 - 20,000 years ago:
(Note: The dates given for the Old Crow and Topper digs have not
been completely accepted by the archaeology community.)
- Geneticists have variously estimated that peoples of Asia and
the Americas were part of the same population from 21,000 to 42,000
(Note: The conclusions reached in Alberta on dates have not been
accepted by the entire archaeology community.)
- Ice-free corridor running north and south
through Alberta and the
continental glacier called
Laurentide ice sheet.
by geologists in the 1950s when stone tools were found in the
Grimshaw, Bow River and in Lethbridge Alberta, under glacial sand and gravel are believed
to be pre-glacial and therefore may indicate nomadic
humans occupied the area. A child's skull found in 1961 near
Alberta is believed to be one of the oldest inhabitants
discovered in Alberta.
- Siberian mammoth hunters believed to
have penetrated far into the Arctic where
ice-free corridors north during the time are believed found. Theory
first introduced by geologist in the late 1970s when core samples
indicate ice is no older then 17,000 year old.
|23,000 - 16,500 years ago:
- 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 the European
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.
- Genetic evidence (2007-2009) suggests the Beringia population
first genetic diversification from Asian populations occurred. 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,
thereby refuting multiple-migration models.
|16,500 - 13,000 years ago:
- Geologists report this is when 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.
- Age estimates based on Y-chromosome micro-satellite place
diversity of the American Q-Haplo at around 10,000 to 15,000 years
- Mass extinction of large fauna begins due to climate change and
perhaps hunting. The Dire Wolf, Smilodon, Cave Lion,
Giant beaver, Ground sloth, Mammoth, American Mastodon, American Camel, American
Equine, and American lion all
become extinct by 11,000 years ago.
- Pre-Clovis sites uncovered from 1973-1978
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
- 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 1977-1985. A
coastal migration could explain how people arrived in Monte
archaeologists say people were living at Cactus Hill, Virginia where stone tools and charcoal from a fire pit are
|15,000 - 13,000 years ago:
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 l976 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
- 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.
Caves in the Cascade Range of Oregon,
archaeologists find a scattering of human coprolites, or fossil feces in 2003. 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.
|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
- 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. 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
- Peru coastal
region inhabitants fished with nets and bone hooks, collecting
seafood such as crabs and sea urchins.
|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.
- 1994, University of California, Riverside anthropologist R.
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.
- Unique markers found in DNA recovered from an Alaskan tooth
were found in specific coastal tribes, and were rare in any of the
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
|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. 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 6000
to over 8500 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 indicates that such sites almost certainly
exist. Lack of funding for exploration in the areas has
postponed likely finds.
- 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 to be used in the same valley between
7,000 - 6,000 years ago.
that Amerindian populations derived from a theoretical single
, possibly from
only 50 to 70 genetic contributors. Preliminary research,
restricted to only 9 genomic regions (or loci
) have shown a genetic link between
original Americas and Asia populations. The study does not address
the question of separate migrations for these groups, and excludes
other DNA data-sets.
The American Journal
of Human Genetics
released an article in 2007 stating "Here we
show, by using 86 complete mitochondrial genomes
that all Indigenous Americans haplogroups
, including Haplogroup X
, were part of a single
founding population." Amerindian groups in the Bering Strait region
exhibit perhaps the strongest Haplogroup Q1a3a
to Siberian peoples
. The genetic
diversity of Amerindian indigenous groups increase with distance
from the assumed entry point into the Americas. Certain genetic
diversity patterns from West to East suggest at least some coastal
migration events. Geneticists have variously estimated that peoples
of Asia and the Americas were part of the same population from
42,000 to 21,000 years ago. To be sure, Amerindian groups in the
Bering Strait region exhibit perhaps the strongest DNA or
mitochondrial DNA relations to Siberian peoples. The genetic
diversity of Amerindian groups seems to increase with distance from
the assumed entry point into the Americas. Certain genetic
diversity patterns from West to East may suggest at least some
coastal migration events.
American Journal of Physical Anthropolog 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 (Eshleman et al. 2004)
showed that mtDNA (human
) from indigenous populations in coastal
British Columbia showed similarities to coastal populations in
Southern California, while inland populations in both localities
Land bridge theory
Also known as the Bering Strait Theory or Beringia
theory, the Land Bridge theory has been
widely accepted since the 1930s. This model of migration into the New World
proposes that people migrated from Siberia into Alaska, tracking
big game animal herds. They were able to
cross between the two continents by a land bridge called the
Bering Land Bridge, which spanned
what is now the Bering
Strait, during the Wisconsin glaciation, the last major
stage of the Pleistocene beginning
50,000 years ago and ending some 10,000 years ago, when ocean
levels were lower than today.
This information is gathered
using oxygen isotope
. An exposed land bridge
that was at least 1,000 miles wide existed between Siberia and the
western coast of Alaska. In the "short chronology" version, from
the archaeological evidence gathered, it was concluded that this
culture of big game hunters crossed the Bering Strait at least
12,000 years ago and could have eventually reached the southern tip
of South America by 11,000 years ago.
At some point during the last Ice Age
17,000 years ago, as the ice sheets advanced and sea levels fell,
people first migrated from the Eurasian
landmass to the Americas
. These nomadic hunters were following
game herds from Siberia across what is today the Bering Strait into Alaska, and then
gradually spread southward. Based upon the distribution of Amerind
languages and language families, a
movement of tribes along the Rocky
Mountain foothills and eastward across the Great Plains to the Atlantic seaboard is assumed to have occurred at least some
13,000 to 10,000 years ago.
This big game-hunting culture has been labeled the Clovis culture,
and is primarily identified with fluted projectile points.
culture received its name from artifacts found near Clovis, New
Mexico, the first evidence of this tool complex, excavated
The Clovis culture ranged over much of North
America and appeared in South America. The culture is identified by
distinctive "Clovis point", a flaked flint spear-point with a
notched flute by which it was inserted into a shaft; it could then
be removed from the shaft for traveling. This flute is one
characteristic that defines the Clovis point complex.
Dating of Clovis materials has been by association with animal
bones and by the use of carbon dating
methods. Recent reexaminations of Clovis materials using improved
carbon-dating methods produced results of 11,050 and 10,800
radiocarbon years B.P. (before
). This evidence suggests that the culture flowered
somewhat later and for a shorter period of time than previously
believed. Michael R. Waters of Texas
A&M University in College Station and Thomas W.
Jr., proprietor of a private-sector laboratory in Lafayette,
Colorado and an expert in radiocarbon dating attempted to
determine the dates of the Clovis period.
The heyday of
Clovis technology has typically been set between 11,500 and 10,900
radiocarbon years B.P. (The radiocarbon calibration is disputed for
this period, but the widely used IntCal04 calibration puts the
dates at 13,300 to 12,800 calendar years B.P.). In a controversial
move, Waters and Stafford conclude that no fewer than 11 of the 22
Clovis sites with radiocarbon dates are "problematic" and should be
disregarded—including the type site in Clovis, New Mexico. They
argue that the datable samples could have been contaminated by
earlier material. This contention was received as highly
controversial by many in the archaeological community.
Clovis-type artifacts seem to disappear from the archaeological
record after the hypothesized Younger Dryas impact event
roughly 12,900 years before the present. The effects of the event
possibly caused a decline in post-Clovis human populations and
shifts in culture and behavior patterns.
Problems with Clovis migration models
Significant problems arise with the Clovis migration model. If
Clovis people radiated south after entering the New World and
eventually reached the southern tip of South America by 11,000
years ago, this leaves only a short time span to populate the
entire hemisphere. Another complication for the Clovis-only
theory arose in 1997, when a panel of authorities inspected the
Verde site in Chile, concluding
that the radiocarbon evidence predates
Clovis sites in the North American Midwest by at least 1,000
This supports the theory of a primary coastal
migration route that moved South along the coastline faster than
those that migrated inland into the central areas of the Americas.
Many excavations have uncovered evidence that subsistence patterns
of early Americans included foods such as turtles
. This is quite a change of diet from
the big game mammoths
, long-horn bison
, and camels
that early Clovis hunters apparently followed
east into the New World.
Topper archaeological site (located along the
banks of the Savannah River near
South Carolina) investigated by University
of South Carolina archaeologist Dr. Albert
Goodyear, charcoal material recovered
in association with purported human artifacts returned radiocarbon dates of up to 50,000 years
This would indicate the
presence of humans well before the last glacial period
considerable doubt over the validity of these findings has been
raised by many other researchers, and the pre-Clovis Topper dates
Pre-Clovis dates have been claimed for several sites in South America
, but these early dates have yet
to be verified unequivocally.
Recent discoveries of human coprolites
(desiccated feces) found deeply buried in an Oregon Cave, indicates
the presence of humans in North America as much as 1,200 years
prior to the Clovis culture.
Watercraft migration theories
Earlier finds have led to a pre-Clovis
theory encompassing different migration models with an
expanded chronology to supersede the "Clovis-first" theory.
Pacific coastal models
Pacific models propose that people reached the Americas via
water travel, following coastlines from northeast Asia into the
Coastlines are unusually productive environments
because they provide humans with access to a diverse array of
plants and animals from both terrestrial and marine ecosystems.
exclusive of land-based migrations, the Pacific 'coastal migration
theory' helps explain how early colonists reached areas extremely
distant from the Bering Strait region, including sites such as
Verde in southern Chile and Taima-Taima in western
Two cultural components were discovered at
Monte Verde near the Pacific Coast of Chile. The youngest layer is
radiocarbon years (~14,000 cal BP) and has produced the remains of
several types of seaweeds collected from coastal habitats. The
older and more controversial component may date back as far as
33,000 years, but few scholars currently accept this very early
Other coastal models, dealing specifically with the peopling of the
coasts, have been advocated by archaeologists Knut Fladmark, Roy
Carlson, James Dixon, Jon Erlandson, Ruth Gruhn, and Daryl Fedje.
In a 2007 article in the Journal of Island and Coastal Archaeology,
Erlandson and his colleagues proposed a corollary to the coastal
migration theory—the kelp highway hypothesis—arguing that
productive kelp forests supporting similar suites of plants and
animals would have existed near the end of the Pleistocene around
much of the Pacific Rim from Japan to Beringia, the Pacific
Northwest, and California, as well as the Andean Coast of South
America. Once the coastlines of Alaska and British Columbia had
deglaciated about 16,000 years ago, these kelp forest (along with
estuarine, mangrove, and coral reef) habitats would have provided
an ecologically similar migration corridor, entirely at sea level,
and essentially unobstructed.
As early as 1787
Chilean naturalist Juan Ignacio Molina
possibility of South America being populated from south Asia
through the "infinite island chains" of the Pacific while north
America could have been populated from Siberia. Some anthropologists
such as Paul Rivet have proposed that
peoples of Oceania or southeast Asia crossed the Pacific Ocean and arrived in South
America long before the Siberian hunter-gatherers.
hypothetical Pre-Siberian American
populated much of South America before being nearly
exterminated and/or absorbed by the Siberian migrants coming from
the north. Some of the theories involve a southward
migration from or through Australia and
Tasmania, hopping Subantarctic islands and then
proceeding along the coast of Antarctica and/or southern ice sheets
to the tip of South America sometime
during the last glacial
There have been well-dated stratigraphic
studies that point to people
entering Australia some 40,000 years ago. At this period Australia
was not connected to another continent, which leads to the
assumption that it was reached by watercraft
. If Australia was reached in this
fashion, some reason that the New World could have been reached in
the same way. Proponents of this model have pointed to cultural and
phenotypical similarities between the Aboriginal
of Australia and the
tribes of southern Patagonia
. The theory
of Australoid migration to the Americas has earned little
scientific support as there is no genetic evidence matching
indigenous Australians with South American populations. This model
is taught in Chilean schools together with the land bridge model
A recent study claimed that the Mapuche
chicken came from
by analysing their DNA
;    
this suggests a more recent contact
between the Mapuche and Polynesia. Another recent study has
contradicted this claim stating that the DNA found in the chicken
bone was closer to post colonial European chickens. 
the earliest known sites of human occupation in the Americas,
Verde, lies within what was later to become Huilliche territory, although there is currently
no demonstrated link between the Monte Verde people and the
Southeast Asians: Paleoindians of the Coast
The boat-builders from Southeast Asia may have been one of the
earliest groups to reach the shores of North America
. One theory suggests people in boats
followed the coastline from the Kurile Islands to Alaska down the
coasts of North and South America as far as Chile [2 62; 7 54,
57]. The Haida nation on the
Charlotte Islands off the coast of British Columbia may have originated from these early Asian mariners
between 25,000 and 12,000. Early watercraft migration would also
explain the habitation of coastal sites in South America such as
Pikimachay Cave in Peru by 20,000
years ago and Monte
Verde in Chile by 13,000
years ago [6 30; 8 383].
- "'There was boat use in Japan 20,000
years ago,' says Jon Erlandson, a University of Oregon anthropologist. 'The Kurile Islands
(north of Japan) are like stepping stones to Beringia,' the then
continuous land bridging the Bering Strait. Migrants, he
said, could have then skirted the tidewater glaciers in Canada
right on down the coast." [7 64]'
Atlantic coastal model
Archaeologists Dennis Stanford
Bruce Bradley champion the coastal Atlantic route. Their Solutrean Hypothesis
is also based on
evidence from the Clovis complex, but instead traces the origins of
the Clovis toolmaking style to the Solutrean
culture of Ice Age Western Europe. They
have hypothesized that Solutrean hunters and fishers may have
worked their way along the southern margins of the Atlantic sea ice
to North America. Their argument is based on technological analysis
of the similarities between Solutrean and Clovis flint-knapping
techniques. Their book on the Solutrean Hypothesis is scheduled for
publishing in 2009.
Other Atlantic migration proponents include the French
archaeologist Remy Cottevieille-Giraudet, who in the 1930s
suggested a European Cro-Magnon
the Algonquian peoples
. In 1963,
Emerson Greenman proposed a hypothetical Atlantic migration during
the Upper Paleolithic, also citing New World similarities with
Solutrean tools as well as art. He suggested that the Beothuk people of Newfoundland, among others, may have been at least partial
descendants of that migration.
According to a research
report on Beothuk DNA published in 2007, " the data do not lend
credence to the proposed idea that the Beothuk (specifically,
Nonosabasut) were of admixed (European-Native American)
Problems with evaluating coastal migration models
The coastal migration models provide a different perspective on
migration to the New World, but they are not without their own
problems. One of the biggest problems is that global sea levels
have risen over 100 metres since the end of the last glacial
period, and this has submerged the ancient coastlines which
maritime people would have followed into the Americas. Finding
sites associated with early coastal migrations is extremely
difficult—and systematic excavation of any sites found in deeper
waters is challenging and expensive. If there was an early
pre-Clovis coastal migration, there is always the possibility of a
“failed colonization.” Another problem that arises is the lack of
hard evidence found for a “long chronology” theory. No sites have
yet produced a consistent chronology older than about 12,500
radiocarbon years (~14,500 calendar years) , but South America has
still seen only limited research on the possibility of early
The Dyukhtai of Northeast Asia
Archaeological sites found in Dyukhtai Cave
and other sites in the Aldan River valley have yielded remains of a culture that may
be a potential Paleoindian ancestor.
This culture occupied
the region from 35,000-12,000 years ago. The Dyukhtai or
similar Northeast Asian cultures may have entered the New World
through Beringia and spread into British Columbia [1 140]. It is thought that they pursued Pleistocene mammals such as the giant beaver,
goats, elk, ancient reindeer (early caribou), horses, Yukon camels,
steppe bison, musk ox, mastodons, and woolly mammoths.
The chief characteristic of the Dyukhtai was their manufacture of
microliths or microblades
Microblades are small flakes less than 1 1/4 inches long, with
a sharp edge and a "backed" or blunted edge that could be guided
with the index finger to sever meat from a carcass. Microblades
could also be incorporated into composite tools such as an arrow or
sickle. Thousands of microblades have been found at upper Paleolithic
Stone Age sites. They have been found
north of Mongolia together with projectile points and hand-carved
The earliest of several sites there has
been dated at 45,000 years ago. Microblades appeared in Japan by 20,000
during the LGM when the island was still a peninsula and reachable
by land [1 144, 202; 3 189-191].
Microblade manufacture was an important event in human history and
its appearance corresponds roughly to the end of the Middle
Paleolithic 60,000 years ago. Over 98% of all human history is
encompassed by the period of time that began with the appearance of
[e.g. "Lucy"]--a maker and user
of Oldowan chopper tools—and ended with the manufacture of
microblades by lower-upper Stone Age cultures such as the
- 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
- 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.)
- Dickason, Olive. Canada's First Nations: A History of the
Founding Peoples from the Earliest Times. 2nd edition. Toronto:
Oxford University Press, 1997.
- Richmond, G.M. and D.S. Fullerton, 1986, "Summation of
Quaternary glaciations in the United States of America", in
Quaternary Science Reviews, vol. 5, pp. 183-196.
- # 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
- PLoS Genet 3(11): e185. doi:10.1371/journal.pgen.0030185
- "DNA Ties Together Scattered Peoples," Los
Angeles Times (accessed September 11, 2006)
- Evidence for an extraterrestrial impact 12,900
years ago that contributed to the megafaunal extinctions and the
Younger Dryas cooling - Firestone et al. 104 (41): 16016 -
Proceedings of the National Academy of Sciences
- Fossilized human feces rewrite ancient history
- The Geographical, Natural and Civil History of Chili,
- Melanie Kuch, Darren R. Gröcke, Martin C. Knyf, M. Thomas P.
Gilbert, Ban Younghusband, Terry Young, Ingeborg Marshall, Eske
Willerslev , Mark Stoneking , Hendrik Poinar, "A preliminary
analysis of the DNA and diet of the extinct Beothuk: A systematic
approach to ancient human DNA" American Journal of Physical
Anthropology Volume 132 Issue 4, Pages 594 - 604 
- Dixon, E. James. Quest for the Origins of the First Americans.
University of New Mexico Press. 1993.
- Dixon, E. James. Bones, Boats, and Bison: the Early Archeology
of Western North America. University of New Mexico Press.
- Erlandson, Jon M. Early Hunter-Gatherers of the California
Coast. Plenum Press. 1994.
- Erlandson, Jon M. The Archaeology of Aquatic Adaptations:
Paradigms for a New Millennium. Journal of Archaeological Research,
Vo. 9, 2001. Pp. 287-350.
- Erlandson, Jon M. Anatomically Modern Humans, Maritime
Migrations, and the Peopling of the New World. In The First
Americans: The Pleistocene Colonization of the New World, edited by
N. Jablonski, 2002. Pp. 59-92. Memoirs of the California
Academy of Sciences. San Francisco.
- Erlandson, Jon. M., M. H. Graham, Bruce J. Bourque, Debra
Corbett, James A. Estes, & R. S. Steneck. The Kelp Highway
Hypothesis: Marine Ecology, The Coastal Migration Theory, and the
Peopling of the Americas. Journal of Island and Coastal
Archaeology, Vo. 2, 2007. Pp. 161-174.
- Jason A. Eshleman, Ripan S. Malhi, and David Glenn Smith,
"Mitochondrial DNA Studies of Native Americans: Conceptions and
Misconceptions of the Population Prehistory of the Americas",
Evolutionary Anthropology, 12:7–18 (2003)
- Fedje, & Christensen. Modeling Paleoshorelines and Locating
Early Holocene Coastal Sites in Haida Gwaii. American Antiquity,
Vol. 64, #4, 1999. Pp. 635-652.
- E. F. Greenman, "The Upper Palaeolithic and the New World",
Current Anthropology, 4: 41–66 (1963)
- 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).
- Jones, Peter N. Respect for the Ancestors: American Indian
Cultural Affiliation in the American West. Bauu Institute Press.
- Matson and Coupland. The Prehistory of the Northwest Coast.
Academic Press. New York. 1995.
- Bradley, Michael, "The Black Discovery Of America: Amazing
evidence of daring voyages by ancient West African mariners"
Toronto, Canada: Personal Library Publishers, 1981 ISBN
- Adovasio, J. M., with Jake Page. The First Americans: In
Pursuit of Archaeology’s Greatest Mystery. New York: Random
- Bradley, B. and Stanford, D. "The North Atlantic ice-edge
corridor: a possible Palaeolithic route to the New World."
World Archaeology 34,
- Bradley, B. and Stanford, D. "The Solutrean-Clovis connection:
reply to Straus, Meltzer and Goebel." World Archaeology 38, 2006.
- Lauber, Patricia. Who Came First? New Clues to
Prehistoric Americans. Washington, D.C.: National Geographic
- Snow, Dean R. “The First Americans and the Differentiation of
Hunter-Gatherer Cultures.” In Bruce G. Trigger and Wilcomb *E.
Washburn, eds., The Cambridge History of the Native Peoples of
the Americas, Volume I: North America (Cambridge: Cambridge University Press,
- Jones, Peter N. "Respect for the Ancestors: American Indian
Cultural Affiliation in the American West." Boulder, CO: Bauu
- Dixon, E. James. Bones, Boats and Bison: the Early Archeology
of Western North America. University of New Mexico Press.
- Evidence Supports Earlier Date for People in North
America, April 4, 2008
- Gowlett, John. Ascent To Civilization. New York: Alfred A.
- Petit, Charles W. "Rediscovering America." U. S. News &
World Report, October 12, 1998.
- Fagan, Brian M. The Journey from Eden. London: Thames and
- Gilsen, Leland. "Pleistocene Adaptations." May 29, 1999. Oregon
Archaeology: Prehistory. June 2, 2000 .
- Beringia Research. Yukon Beringia Interpretative Centre. Dec.
7, 2000 .
- Coe, Michael, Dean Snow, and Elizabeth Benson. Atlas of Ancient
America. New York: Facts On File Publications, 1986.
- Begley. Sharon and Andrew Murr. "The First Americans."
Newsweek, April 26, 1999.
- Roosevelt, A. C. et al. "Paleoindian Cave Dwellers in the
Amazon: The Peopling of the Americas." Science, April 19,
- Price, Douglas and Gary Feinmen, editors. "Monte Verde Early
Hunter-Gatherers in South America." Images of the Past. 1997.
- Surovell, Todd A. "Early Paleoindian Women, Children, Mobility,
and Fertility." American Antiquity, 65 (3), 2000