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Chiquihuite Cave, located in the Astillero Mountains of Zacatecas, Mexico, at 2,740 meters altitude, contains evidence suggesting human activity during the Ice Age, between 26,000 and 18,000 years ago. Researchers found undisturbed soil layers, stone tools, and signs of fire use, indicating early human presence. The tools, made from selected limestone, showcase a unique technology not linked to known ancient cultures, highlighting the adaptability and resourcefulness of these people.
The cave's environment shifted from Ice Age forests to open grasslands, as shown by plant and animal DNA, reflecting climate changes. Similar tools found elsewhere in South America hint at diverse, localized technologies across early American populations.
However, skepticism remains. Some argue that the stone artifacts may be naturally fractured rocks, and evidence for human presence is inconclusive. The claim of human occupation over 30,000 years ago challenges existing migration timelines, but further evidence is needed before revising current theories.
Key Points of Early Human Migration into the Americas
1. Timing of Arrival
Clovis-first Model Challenged: Originally posited human arrival around 13,000 years ago, but recent findings date human presence to over 16,000 years ago.
Pre-Clovis Migration: Evidence suggests Paleo-Indian dispersal began prior to the Last Glacial Maximum (LGM), indicating early human habitation in the Americas.
2. Migration Routes
Bering Land Bridge: Traditionally accepted as the main route for entry.
Coastal Route Hypothesis: Emerging evidence suggests a parallel coastal migration along the Pacific, possibly more suitable during ice-covered inland periods.
3. Cultural and Technological Diversity
Beyond Clovis Culture: Diverse tool traditions, such as the Western Stemmed Tradition, indicate multiple cultures coexisted across the Americas.
Regional Innovation: Artifacts like South American Fishtail points reveal distinct regional advancements and adaptations.
4. South American Populations
Independent Cultural Developments: Adaptation in unique environments led to innovative, distinct South American lithic traditions (e.g., Bifacial and Edge-Trimmed).
Ecosystem-Specific Ingenuity: Early settlers adapted tools and techniques to fit diverse ecosystems, showcasing a wide array of survival strategies.
5. Genetic Evidence and Ancestral Lineages
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[Music]
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chihou cave is located high in the Estero mountains of zakus Mexico at an
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altitude of 2,740 M it is about 1,000 m above the
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surrounding Valley the cave was formed millions of years ago from ancient Limestone and features two large
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chambers that are more than 50 m wide and 15 M tall the floor of the cave is
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covered in debris from roof collapses and mudslides which sealed It Off by the end of the Ice Age researchers have
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uncovered layers of soil and artifacts and found signs of human activity in the cave dating back to the Ice Age roughly
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26,000 to 18,000 years ago these layers show a pattern of changing wet and dry
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conditions over time what's important is that the layers were not Disturbed Meaning they have remained in their
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original position two layers of soil stood out in particular a thick orange
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brown layer that separates older deposits from the Ice Age from newer ones after the Ice Age A hardened
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surface above suggests a dry stable period at the end of the Ice Age these
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stable times may have been when humans lived in the cave as conditions were more favorable during the coldest parts
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of the Ice Age the area near the cave was forested with trees like Juniper fur fur Pine and Spruce as the climate
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warmed these forests gave way to open areas with Joshua trees and grasses DNA
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from the cave soil also revealed the presence of animals like bats rodents bears and goats burnt plants and
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charcoal suggest that early humans used fire possibly for cooking or staying warm researchers also found stone tools
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made from carefully chosen Rock showing that these people were skilled and resourceful stone tools found in the
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cave included scrapers blades and knives made by chipping stones to create sharp
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edges the tools were crafted from green and black Limestone which was stronger and easier to work with than the gray
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Limestone inside the Cave the people who lived here seemed to have a deep
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understanding of their environment and selected materials carefully the tools were unique showing a style not seen in
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other ancient cultures in the American they reflected the creativity and Ingenuity of the Cave's inhabitants
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while no human DNA was found other Clues suggest human presence burnt remains of
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plants Ash and traces of fire all point to human use of the cave chemical
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residues in the soil and the many stone tools are additional evidence of their
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activities over thousands of years the cave surroundings shifted from dense forests during the Ice Age to grassy
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open air areas as the climate warmed DNA from ancient and modern
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horses also revealed how animals changed in response to these shifts
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interestingly similar tools like those found in Chiki cave have been found in other parts of South America like Brazil
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though these tools also don't match known traditions this suggests that early humans in the Americas had diverse
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Technologies and adapted to different environments across the continent if confirmed this evidence would push back
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the timeline of human arrival in the Americas by thousands of years it also shows that early humans were resourceful
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and capable of surviving in harsh Ice Age environments with unique Technologies the evidence from chit cave
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and other archaeological sites in the Americas suggest that humans may have been present on the continent much
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earlier than previously believed possibly before the last glacial maximum
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the diversity of tools found across the Americas such as blades scrapers and bifacial tools shows that early
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populations adapted to their local environments tools evolved over time through local Innovations which were
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sometimes shared among groups this explains the differences seen in the archaeological record across regions at
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Chiki weti tools were made from silica Rich limestone a practice also seen in South America at sites like Santa Elina
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in Brazil the use of local materials and techniques was a common feature of ancient tool making however the
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similarities between these sites highlight how technology could be shared or independently developed for a long
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time many archaeologists believed humans arrived in the Americas after the last glacial
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maximum the evidence from Chate and other sites challenges this view
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suggesting humans were present much earlier potentially over 30,000 years ago however the hypothesis that Kiki
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cave shows evidence of early human presence in the Americas and a unique stone tool industry is unconvincing the
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stone pieces described as tools could have formed naturally due to the conditions in the cave where rocks
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frequently break apart there is a lack of enough evidence to prove that the stones were shaped by humans more
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detailed work is needed to show that these stones are not just naturally broken rocks but were purposefully made
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by people stronger evidence is required before revising the current understanding of early human migration
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to the Americas the claim that humans lived in the cave as far back as 33,000 years ago challenges the existing
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understanding of how and when people first arrived in the
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[Music] Americas the question of when how and by
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whom the Americas were first inhabited has been a longstanding and highly
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debated Topic in archaeology scientists have been intrigued by key questions when did humans first arrive
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in the Americas what kind of people were they and what route did they take to reach the new world these queries have
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fascinated researchers since Columbus landed in the Bahamas in 1492 many archaeologists initially
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believe that the first humans in the Americas entered through the bearing landbridge when it was still above water
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intense debates exist regarding the specifics of human settlement in the Americas controversies revolve around
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three fundamental questions how long ago did humans first settle in the Americas
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what tools did they bring and what was their way of life what was the ancestral origin of the first Native Americans
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even after the discovery of fome excavations controversies surrounding the initial settlement of the Americas
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have persisted and continue to be one of the most vigorous debates in the field the fom excavations refer to a
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significant archaeological Discovery in fome New Mexico that Dr atically altered our understanding of early human life in
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North America the fome site excavated in the late 1920s revealed evidence of early
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humans hunting now extinct species of Bison using a distinct style of projectile points called fome points
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these finely made fluted spear points were found embedded in the bones of Bison antiquus a larger relative of the
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modern bison establishing a clear connection between humans and these animals
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the discovery was groundbreaking because it pushed back the timeline for human presence in North America to over 10,000
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years ago dating to the Paleo Indian period around 10 to 8,000 BC before the
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fome excavations it was commonly believed that humans had only arrived in the Americas around 4 to 5,000 years ago
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the careful Association of stone tools with extinct animals provided the first conclusive evidence of human activity in
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the continent dur during the late Pine the folsome site is now considered one of the most important archaeological
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finds in the history of North American prehistory and it contributed to the identification of the fulam culture
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which is distinct from the later Clovis culture but just a few years later another Discovery would push the
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boundaries of our understanding even further in Blackwater Draw near Clovis New Mexico archaeologists found even
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older tools massive fluted spear points used to hunt mammoths and other Ice Age
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meapa these Clovis points dating back 13,000 years revealed the existence of
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an ancient culture that spread across much of North America the Precision of
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the tools and their wide distribution suggested a highly organized mobile
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Society of hunter gatherers until recently the widely accepted theory about the first humans in the Americas
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suggested that big game Hunters arrived around 13 ,000 years ago from Asia
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Crossing through a corridor between ice sheets once below the 48th parallel
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North it was thought that these people developed the Clovis tradition dated to around 13 to 12,000 years ago which
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spread across North America this idea known as the Clovis first model
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dominated much of the 20th century however new archaeological evidence has challenged this Theory revealing sites
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and technological industries that predate Clovis as a result the earlier narrative has been debunked and A New
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Perspective suggests that an earlier dispersal route along the Pacific coast is the more likely means by which humans
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initially entered the Americas around 13,500 years ago people had spread
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across both North and South America with a unique group known as the Clovis culture emerging in what is now the
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Southeastern and southwestern United States the Clovis people are best known for their distinct stone tools
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particularly their fluted lanolate points which were carefully crafted through a technique called bifacial
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reduction these tools were highly effective for hunting and the Clovis culture became widely recognized for
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this technological advancement another key aspect of their toolkit was the core and blade technology where large blades
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were made from special cores and then used as tools or left unmodified while
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there's debate about whether this technology originated in Eurasia or evolved independently in America it's
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clear that the signature Clovis point was an American innovation early discoveries of Clovis tools were often
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associated with the hunting of large Ice Age animals like mammoths leading early archaeologists to label the Clovis
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people as big game Hunters famous sites like Blackwater Draw in New Mexico and
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Murray Springs in Arizona revealed evidence of such hunts but these megap fonal kill sites were actually quite
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rare as more Clovis sites were discovered such as base camps like the G site in Texas it became evident that
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Clovis people had a broader diet than previously thought they hunted small game and likely gathered plants as well
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this more varied subsistence strategy challenges the idea that they were primarily focused on large prey though
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hunting mammoths and other big animals still played a significant role in their lifestyle glovis technology is mostly
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concentrated in Southeastern North America but it also spread to other regions including the Great Plains and
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even as far as Alaska some researchers suggest that these widespread Clovis artifacts could have been the result of
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people moving across the continent While others think it might simply reflect the spread of Technology through trade or
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cultural diffusion for years archaeologists believe that Clovis culture Spann from about
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13,400 to 12,800 years ago however more recent studies suggest it might have
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been much shorter perhaps only lasting 2 to 300 years this idea sparked debate
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because such a short time frame seems too brief for the clois people to spread their culture across such vast
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distances while some sites like Aubrey in Texas suggest an earlier timeline the
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exact duration of the Clovis period remains unresolved evidence from northern Mexico including a gumer
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prehistoric elephant-like creature kill site hints that Clovis culture might have originated further South than
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previously thought possibly evolving from existing forager populations some
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researchers also propose that early Clovis groups may have traveled along the Pacific coast before moving Inland
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shaping the early human presence in North America the debate over the origins and
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spread of Clovis culture continues but it remains a key chapter in the story of
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the first Americans in Western North America a distinct tool making tradition
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called the Western stem tradition existed during the same period as the Clovis culture if not earlier unlike
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Clovis points which are fluted at the base Western stem tradition points were stemmed with ground edges and were
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typically made from volcanic Stones like obsidian these tools came in various forms and were made using different
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techniques than Clovis tools lacking the overshot thinning seen in Clovis bifaces
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a unique feature of Western stem tradition culture is the use of Crescent shaped bifaces thought to have been used
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as projectile points their exact purpose is unclear though some researchers
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suggest they may have been used to hunt Marsh Birds most western stem tradition
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sites are found around what were once lakes rivers and wetlands particularly in the Great Basin Columbia River
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drainage and along the Pacific coast unlike Clovis people who are associated
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with hunting large animals like mammoths Western stem tradition population appear to have focused on smaller game fish and
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plant-based diets living in areas with abundant Water Resources the Western stem tradition
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people are referred to as paleoarchaic indicating a different lifestyle from their Eastern counterparts like the
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Clovis people Western stem tradition artifacts have been found across a wide range of environments from the Rocky
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Mountains to Baja California and as far north as Alaska and British Columbia the
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timeline of West W stem tradition is still debated some researchers argue that the Western stem tradition existed
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alongside the Clovis culture While others think Western stem tradition could be even older for example at sites
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like Smith Creek cave and bonavilla State's Rock shelter Western stem tradition points were found with early
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radiocarbon dates suggesting that these people lived during the same time as Clovis populations there is also
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evidence from sites like Paisley caves in Oregon and Cooper's Ferry and Idaho
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where Western stem tradition points have been dated to around 13,000 years ago
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overlapping with the Clovis period the exact origin of Western stem tradition technology is still unclear it's
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possible that both Clovis and Western stem tradition Technologies developed
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independently in different parts of the world or that they evolved from an even
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earlier tool making tradition regardless the evidence suggests that the Western
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stem tradition and Clovis cultures existed at roughly the same time each with its own distinct way of life and
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Tool making techniques the early human occupation of South America around 13,000 to 13,500 years ago is
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challenging due to the continent's diverse Landscapes cultures and Technologies in general there were two
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main tool making Traditions during this time the biif ficial tradition and the EDG trimmed tradition the B facial
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tradition is known for its fishtail and El Jobo points which are similar to Clovis and Western stemmed points being
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by facially worked and sometimes fluted The Edge trim tradition on the other hand focused on simpler unifacial tools
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made from cores and flakes these tools have been found from northern South America all the way down to the southern
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tip and there's some evidence of similar traditions in the Eastern parts of the continent the fishtail points found in
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southern South America seem to have been produced by people who hunted meapa like
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ground sloths and horses however direct evidence linking these tools to meapa
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hunting is limited by 13,000 years ago the people of South America had adapted
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to a variety of environments including Coastal mountainous and tropical regions
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each with its own subsistence strategies fishtail points knives scrapers and
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other tools were widely used and many sites without these distinctive points
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suggest other groups were also present at the time there's an ongoing debate
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about the origins of these South American Tool Traditions some researchers think they evolved from
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North America's Clovis culture While others argue they developed independently in South America with the
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earliest fishtail sites in the southern part of the continent notably the fishtail sites in Chile and Argentina
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date back to around 13,000 years ago suggesting long history of human
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presence in these areas other early sites even those without diagnostic Point suggest widespread human activity
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across South America by this time for example sites in Argentina Chile Peru and Brazil all have radiocarbon dates
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from around 13,000 years ago showing a broad and diverse occupation of the continent these findings overlap with
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the later part of the Clovis period in North America indicating that people were well established in South America
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around the same time between 29 and 24,000 years ago the
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earth entered a colder climatic period known as the last glacial maximum which marked the peak of the last ice age this
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period saw a significant drop in temperatures especially in regions like Northeast Asia and North America the ice
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sheets of North America particularly the laurentide and cordilleran ice sheets reached their maximum extent between 25
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and 17,000 years ago this created massive barriers to human migration such as an ice-free corriddor between these
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ice sheets that was closed off around 20,000 years ago with regard to the timing of the initial peopling of the
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Americas three models have been proposed the strict Clovis first dispersal model
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posits that humans arrived only after the development of the Clovis culture around 13,000 years ago this model faces
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challenges because archaeological evidence from sites older than 13,000 years suggests an earlier human presence
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in the Americas the Paleo Indian dispersal model which suggests humans arrived after the last glacial maximum
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around 16,000 years ago has gained the most support this model aligns with
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genetic and archaeological evidence indicating a gradual migration into the Americas before the Clovis period though
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not as early as proposed by some controversial sites the prepa paleo
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Indian dispersal model argues for an even earlier human presence before 16,000 years ago however it faces
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significant challenges due to a lack of strong genetic evidence if this model were accurate it would require the
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existence of populations that were genetically unrelated to Modern Native Americans which conflicts with current
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genetic data showing Native Americans diverged from East Asians between 26 and
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20,000 years ago by around 13,000 to 13,500 years ago people were spread
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across North and South America adapting to various environments and using different subsistence strategies and
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toolkits this period marks the youngest point of the framework for the first human occupation of the Americas however
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since these sites were already occupied by that time it raises the question how long did it take for humans to spread so
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widely and develop such diverse cultures experts generally agree that it would have taken at least 500 to 1,000 years
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if not longer for small groups of foragers to spread across the continents and create the distinct Technologies and
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ways of life seen at these early sites therefore based on the most widely
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accepted early cultural Traditions it seems reasonable to use 14,000 years ago
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as a starting point for human migration into the Americas in recent decades
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genetic Studies have become a key tool in understanding the origins of Native Americans my mitochondrial and Y
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chromosome Hao groups in Native American population suggest that the ancestors of
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Native Americans most likely originated in the alai Mountains region of South Central Siberia near the borders of
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Russia China and Mongolia however this conclusion comes with uncertainties the
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identification of this origin is based on the assumption that populations have not moved significantly over the last
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30,000 years however genetic evidence shows that populations in Eurasia moved
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in many directions during the last ice age some groups stayed in place others
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moved to New areas and populations mixed and split over time for example DNA from
21:40
an ancient burial site in Malta near Lake ball in Siberia dating back 24,000
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years reveals a population called the ancient North eurasians this group was
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genetically related to both Native Americans and Europeans but had already diverged from East Asian
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another burial site Us isim in Western Siberia shows a population that split
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off from ancestors of modern West and East eurasians around 45,000 years ago
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despite these findings there is still no clear picture of how these ancient populations migrated to the Americas
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some evidence suggests a possible connection to populations in Europe because a particular mitochondrial DNA
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Hao Group x2a found in in Native Americans is also found in
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Europeans however this connection is not fully understood and x2a could have
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originated from anywhere in Eurasia ancient North Siberians from Malta
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diverged from West Eurasian populations about 39,000 years ago and disappeared
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as a separate population leaving genetic traces in later ancient and present-- day groups especially among Native
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American populations around 23 to 20,00 years ago there was gene flow between
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the ancient North Siberian group and an East Asian group this interaction led to
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the formation of at least two distinct lineages the ancient paleo Siberians in Northeast Siberia and the basil American
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Branch whose descendants eventually crossed to the Americas the timing of the basil American Branch's formation is
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uncertain one hypothesis suggests it occurred after the last glacial maximum
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around 18,000 years ago however the exact timing remains unclear and it's
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possible that gene flow occurred even before 24,000 years ago as long as it happened after the population
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represented by Malta diverged from the population represented by aano vagora 3
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the emergence of the basil American Branch must have occurred approximately 21 to 20,000 years ago indicating ad
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mixture before the last glacial maximum native Native American individuals show
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ancestry from ancient North Siberians and East Asian populations suggesting
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early geographical isolation possibly in western beringia or further south based
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on the beringian standstill model dispersal into the Americas did not happen immediately but followed an
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extended pause possibly in the region of the bearing land bridge from the
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isolated population of Ancient North Siberians several lineages emerged ancient beringian individuals and
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ancestral Native American individuals these populations crossed into North America in separate movements with
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ancient beringians disappearing around 9,000 years ago although ancient beringians did not continue farther
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south they are genetically closer to other past and present Native American individuals than to any other
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contemporary population the idea of beringian standstill is based on genetic changes observed in North American
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populations suggest tting that these ancestors diverged from their Eurasian relatives thousands of years before
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entering the Americas researchers proposed that this genetic bottleneck likely occurred in beringia setting the
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stage for a rapid spread of these populations into the Americas after the last glacial maximum however if there's
25:17
no solid evidence for a population residing in beringia during this time then the concept of a standstill there
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is also questionable while genetic data could suggest that a population St standstill occurred the exact location
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remains uncertain it could have happened in places like Kamchatka the kural islands sacan Island
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coastal areas of Alaska or even elsewhere in Eurasia in fact evidence
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from archaeology and genetics suggests that the hunter gatherer populations in Northern Siberia likely retreated as
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conditions became colder and drier during the peak of the Ice Age meaning
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beringia may not have hosted a stable
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population most of the last glacial period saw the western part of beringia unoccupied leading to doubts about the
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survival of a small group of people in Central or Eastern beringia while populations in similar environments to
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the West move South some paleo Environmental Studies suggest that
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certain habitats in beringia could have supported human life during the last glacial maximum but contrary data about
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the Region's fauna indicates that the area was largely inhospitable for human settlement during this period for
26:37
instance research found that evidence of human interaction with beringian bison only appears well after the last glacial
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period as the last glacial maximum came to an end around 19 to 15,000 years ago
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temperatures began to rise and the ice started to retreat sea levels also Rose
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gradually as the ice melted by 14,000 years ago the ice sheets had shrunk
27:01
enough to create a narrow Corridor between them but it likely wasn't pass by humans until around 13,500 years ago
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due to the presence of large proglacial lakes Additionally the area may not have been biologically productive enough to
27:17
support human life until around 12,000 years ago while the Inland route was blocked a coastal path from beringia was
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likely only closed between 18 and 15,000 years ago along this Coast there were
27:33
pockets of survivable land which could have enabled people to move by boat the
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rapid climate warming between 15,000 and 14,000 years ago melted the ice sheets
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raising sea levels and flooding coastal areas the date of around 14,500 years
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ago is key for determining whether humans first colonized the Americas during the last glacial period or after
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as conditions before and after this time were vastly different the widely
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accepted theory is that the first people in the Americas crossed the bearing land
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bridge from Asia during the Ice Age this belief is deeply rooted in both
28:14
archaeology and genetics with many studies assuming this migration route without much questioning however the
28:21
actual evidence supporting this theory is surprisingly limited scientific paper ERS regularly
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repeat the idea that the bearing land bridge was the entry point for humans
28:34
into the Americas during the late place to scene around 15,000 years ago or
28:39
earlier this is accepted almost without question even though direct evidence for
28:44
this migration is sparse if there was a population in beringia the area between
28:50
Siberia and Alaska we don't have much evidence of them today partly because much of that land is now submerged
28:57
underwater as archaeologist noted while we assume that the first Americans came from
29:02
Northeast Asia finding proof of their presence in beringia has been challenging the distances between the
29:09
alai mountains believed to be a key region of origin for Native Americans and both the Pacific coast of beringia
29:15
and the Atlantic coast of Norway are nearly identical this raises the possibility that there could have been
29:22
multiple entry points into the Americas perhaps via both the west through beringia and the East Via an Atlantic
29:30
route three main hypotheses propose multiple entry points for the first Americans the ice free Corridor model
29:37
suggests big game Hunters crossed the bearing land bridge and moved South Via an ice free passage between retreating
29:44
ice sheets the saluton hypothesis posits that European foragers navigated the
29:50
North Atlantic Ice margins reaching North America during the last glacial maximum the Pacific Coastal hypothesis
29:57
suggest suggest seaf fairing foragers entered along the Pacific coast and spread Southward currently insufficient
30:05
evidence supports any single Theory and further research is needed to clarify early migration routes the ice free
30:12
Corridor model has long been the dominant theory for the initial peopling of the Americas positing that Siberian
30:18
foragers entered North America around 14,000 years ago through a narrow Corridor between retreating ice sheets
30:25
these foragers equipped with Clovis Style ey faces for hunting megap supposedly spread rapidly across the
30:32
continent leading to the extinction of many P toine species this model is understood in
30:38
relation to Clovis first model and has been supported by several empirical data
30:43
sets these included the presence of Clovis like technology in the vicinity of the corridor the opening of the
30:50
corridor before Clovis sites appeared a trend in the north to south distribution
30:55
of Clovis sites and evidence suggesting Clovis Hunters were responsible for the
31:00
extinction of some megap however critical assessments reveal significant gaps first the claims that there were
31:08
foraging populations in beringia prior to the corridor's opening lack supporting evidence second the dating of
31:16
the corridor remains debated with estimates suggesting it may have opened any time between
31:22
14,500 and 10,500 years ago if we accept an opening around 14,000 years ago
31:29
Clovis Hunters could have reached northern Mexico by 2500 years ago
31:34
contingent on the corridor's ecosystems being conducive to human habitation
31:39
third the conclusions depend on the acceptance of either a long or short Clovis chronology complicating the
31:45
interpretation of age Trends among Clovis sites fourth there is contentious debate on whether Clovis Hunters caused
31:52
megaphon Extinction climate change was responsible or if a combination of factors was at play moreover the
31:59
hypothesis that the rapid spread of Clovis Hunters was due to their specialization in hunting large mammals
32:06
is further called into question the close timing of large mammal extinctions has often been used
32:13
to support the theory of a swift human dispersal but evidence suggests that not
32:18
all extinct species vanished around the same time in fact only about half of the known Genera went extinct after 14,000
32:26
years ago and some survived into the Clovis period finally the question of
32:32
human occupation in the Americas prior to Clovis remains crucial as the evidence for such early human presence
32:38
could challenge the validity of the icef free Corridor model altogether the cutri and hypothesis suggests that early
32:45
humans from Europe known for their cutri and stone tools might have traveled to North America by Crossing ice shelves in
32:51
the North Atlantic during the Ice Age this idea is based on the similarities between saluton tools and Clovis tools
32:59
found in North America hinting at a possible link through shared ancestry or similar
33:05
development however this Theory lacks solid evidence and hasn't been thoroughly tested making it questionable
33:12
some evidence like Marine shells and seal bones found in caves in Spain suggest salitran people use Coastal
33:19
resources but critics say they mostly relied on landbased resources and
33:25
shifting coastlines over time make it hard to inter interpret the theory also relies on the idea that there were ice
33:31
shelves in the North Atlantic which could have allowed for seal hunting but some studies argue that warmer Seas
33:37
would have made these ice shelves rare overall there's little direct proof for this model the age of archaeological
33:45
sites in eastern North America that are thought to be very old 17 to 20,000 years doesn't directly support this
33:51
Theory just extends the timeline the biggest argument for the hypothesis is
33:57
the similarity in tools between the two regions but this could have been independent invention without stronger
34:04
evidence like DNA links or solutran style tools found in North America this
34:10
hypothesis remains speculative and unproven the Pacific coast model
34:16
suggests that human foragers colonize the Americas by navigating the Northern Pacific Coastline moving between islands
34:22
and refugia before dispersing along the coast from beringia while this hypothesis aligns with the timing of the
34:29
last glacial interval it has faced challenges due to the lack of substantial evidence and a clear
34:35
chronology especially considering the inundation of many potential habitation sites by post glacial sea level rise
34:43
support for the Pacific coast model comes from various data including evidence of upper Paleolithic foragers
34:50
using boats in the Japanese archipelago at least 30,000 years ago however the
34:55
extent of coastal adaptation along the kural islands and the Kamchatka Peninsula remains unclear additionally
35:02
some Modern Siberian populations share genetic markers with Native American groups suggesting a potential connection
35:09
although there is no direct evidence of these populations existing during the last glacial maximum while there are
35:15
indications of refugia along the northeastern Pacific coast and evidence of coastal resource use around 13 to
35:22
11,000 years ago key archaeological sites like Mi Verde and Haka PR
35:28
is primarily the basis for earlier Coastal adaptations a variant of this model posits that the use of stemmed
35:35
points by Coastal populations indicates a lineage between Japanese upper
35:40
Paleolithic cultures and those in North America however like the solutrean
35:46
hypothesis this raises the issue of whether these similarities stem from convergent evolution or direct descent
35:53
the model is somewhat bolstered by genetic evidence linking early burials in in the Americas to Coastal
35:59
populations yet it also faces competing theories suggesting multiple migration
36:04
routes including an ice-free Corridor or Arctic Coastal paths in conclusion while
36:11
each model regarding the initial peopling of the Americas whether the Atlantic ice shelf
36:17
model the Pacific coast model or the ice-free corridor model has its
36:23
proponents none can be completely dismissed or fully validated at this stage after reaching Americas the
36:30
ancestral Native American lineage experienced internal splits with the big bar lineage branching off around 21 to
36:38
16,000 years ago another split occurred around 15,700 years ago resulting in Northern
36:45
Native American and Southern Native American populations the big bar lineage moved south from Eastern beringia Alaska
36:53
and the northern Native American southern Native American split like occurred farther south supported by
37:00
genetic evidence showing equidistance to ancient beringian
37:05
individuals ancestral Native American individuals likely crossed beringia and reached North America South of the
37:11
Continental ice sheets before ancient beringian individuals the dispersal patterns of Northern Native Americans
37:18
and Southern Native American populations differed other Native Americans remained in Northern North America eventually
37:25
shifting northward in the hollene Southern Native American populations rapidly spread Southward showing close
37:32
genetic links between ancient individuals in North and South America there were at least two late plac toine
37:39
pulses of Southern Native American groups into South America the genetic history of dogs parallels the human
37:46
peopling process suggesting domestication in Siberia or beringia
37:52
scientists have studied the DNA of many ancient and modern dogs the analysis of
37:57
nuclear DNA shows that all dogss come from three main groups of ancestors one
38:03
from Western Eurasia one from East Asia like dingos and one from the Arctic like
38:10
huskys and ancient American dogs these lineages were established at least
38:16
11,000 years ago ancient DNA studies found a unique
38:24
haa group A2B in preon dogs in the Americas south of the Arctic but it has
38:30
almost disappeared in modern dogs scientists used molecular clock analysis to estimate when these Hao groups split
38:39
the oldest split within Hao group a is estimated to be around 22,800 years ago this suggests that dogs
38:47
were domesticated several thousand years before they appeared in the archaeological record this early
38:53
timeline indicates that dogs were likely domesticated by the time humans migrated into the Americas the relationship
39:00
between the migration of humans and dogs into the Americas during the late pene period is
39:06
fascinating it suggests that dogs may have accompanied the first people entering the Americas and explores the
39:12
timeline of their Divergence the Americas were settled by humans relatively late and it's possible that
39:19
when people first arrived they had dogs with them dogs could have played a role
39:25
in helping humans quickly sprad spread throughout the region comparing the timelines of dog and human populations
39:33
researchers found key points of convergence the introduction of dogs in the Americas is estimated using
39:40
mitochondrial data and it aligns with the timing of human population splits
39:45
ancient American dogs excluding the Arctic belong to the same lineage
39:50
suggesting they coalesced with the Siberian dog lineage around 16,400 years ago this time frame
39:58
coincides with the people of the Americas the evidence indicates that dogs likely cross the beringia land
40:05
bridge during the pine reaching the Americas before later human migrations
40:11
the split between major Native American lineages aligns with the Divergence of dog lineages suggesting they evolved
40:19
together while both ancestral Native Americans and ancient beringians groups could have brought dogs into the
40:25
Americas archaeological evidence hints that ancestral Native Americans might
40:30
have been the first to arrive before the distinctive ancient beringians group
40:35
this suggests a connection between the migration of people and dogs into the Americas during this period ancient DNA
40:43
suggests that dog domestication likely began in Siberia during the late plac toine a period around 26 to 19,700 years
40:52
ago this aligns with the time when humans and their genetically Divergent groups were present in Siberia and
40:58
Western beringia the evidence indicates that human populations in this region were small and lived in relative
41:06
isolation the lack of significant gene flow among these groups and the absence of archaeological sites suggest limited
41:13
interaction with communities outside Siberia as these populations specifically the ancestors of Native
41:20
Americans crossed into the Americas they brought dogs with them the question
41:26
arises how did ancestral Native Americans acquire dogs the researchers proposed that dogs were likely
41:32
domesticated from a wolf population in Siberia or Western beringia during the
41:37
late Pine before ancestral Native Americans migrated into the Americas
41:44
among the various groups present in Siberia during the last glacial maximum the researchers eliminate some
41:50
possibilities and suggest that the ancient North Siberians are the more likely population to have initiated the
41:56
domestication process genomic analyses of ancestral North Siberian individuals
42:01
at Siberian sites show evidence of gene flow into both ancient Native American
42:06
and Western Eurasian lineages this suggests a mechanism for the transfer of
42:11
dogs into different groups supporting their movement both East and West
42:17
following domestication the researchers proposed that climatic conditions during
42:23
the last glacial maximum brought human and wolf population into proximity within refugial areas
42:31
leading to increased interactions Mutual Scavenging of kills or wolves drawn to
42:36
human campsites may have initiated a shift in the relationship between humans and wolves eventually resulting in dog
42:45
domestication no genomic evidence supports the controversial claim that the First Peoples came from Europe via
42:51
the North Atlantic claims about paleoamericans having different ancestry possibly
42:57
related to European or other populations have been rejected all ancient human
43:03
genomes from the Americas except for later arriving paleo Inuit and Inuit Thule groups show closer affinities to
43:10
contemporary Native American peoples than to any other present-day populations worldwide during the holos
43:17
scene human migration continued between Northeast Asia the bearing straight and
43:22
the Americas the earliest evidence of bearing straight Crossings is seen in the ocean Bay tradition around 5,200
43:30
years ago athabascan groups in Northern North America show East Asian genetic
43:36
ancestry from gene flow around 5,000 to 4,400 years ago likely from Proto paleo
43:43
Eskimos the North American Arctic saw two major cultural Traditions the Paleo
43:49
Inuit around 5,200 to 1500 BC and the tulle culture ancestors of today's Inuit
43:57
spreading around 200 BC there's evidence of back migration from the Americas to
44:04
Siberia in the Americas ancient populations rapidly expanded but
44:09
remained largely settled after initial migrations groups like The Clovis and fishtail cultures which appeared after
44:17
13,500 years ago spread widely across the continents despite challenging
44:23
conditions many populations persisted in isolation such as the ancient beringians
44:29
who left no modern Descendants the Andes in islands like British Colombia show
44:34
genomic differences caused by both Geographic and social isolation in the
44:40
Caribbean and mesoamerica gene flow occurred particularly during the
44:45
expansion of the Inca Empire Polynesian and Native American contact in the Eastern Pacific around the 13th century
44:52
suggests interactions between these distant populations there is no no substantial evidence supporting the
44:59
existence of a beringian population that remained isolated during the last glacial maximum only to rapidly expand
45:07
into the Americas as conditions improved while there is genetic evidence
45:13
for a population bottleneck the specifics regarding its location cause
45:19
and mechanisms are speculative at best archaeological and genetic data indicate
45:25
that the foraging populations in Northern Siberia likely retreated Southward and abandoned at least the
45:31
western part of beringia during the harsh conditions of the last glacial maximum challenging The Narrative of a
45:39
stable isolated population waiting to spread into the Americas
45:47
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