It is well understood by seasoned scholars of any discipline
that the more we learn about a topic the more we realize that we actually know
less and less. The reason for this
paradox is that research often brings about new research questions that must be
answered, which is both good and bad.
This leads to further research but causes us to not truly understand the
problem or topic we were initially seeking to solve or know. One such situation is the case of archaeologists
being perplexed over many decades on how specifically humans came to the New
World (aka, the Americas). Evidence
existed and demonstrated human occupations across the New World at very
different times, resulting in heated debate among scholars and outright refusal
in some cases to believe the existing evidence, but with time comes greater
advances in ways of studying the past and ultimately clarity. Today’s blog post is going to discuss what we
used to know versus what we now know regarding the peopling of the New World.
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| Figure 1: Clovis point |
Archaeologists first stumbled upon the debate regarding the
peopling of the New World when they tried to pin down the earliest human
occupation in the New World. Scholars
had discovered significant evidence of material culture associated with what
they called the “Clovis” culture (named after Clovis, New Mexico, where the
original artifacts were found) (Figure 1). The
Clovis culture (or tradition) is a Paleoindian culture characterized by long, bifacial stone points that are also
fluted on each side. Several Clovis
points had been found across North America, which validated the existence of
humans in North America as early as 13,500 years ago. Archaeologists believed that the Clovis
people came to the New World by land through an ice-free corridor along the Bering land
bridge, which was a large land mass that existed between Siberia (in Asia) and Alaska (in North America) that today is islands but was not in the past (Figure 3). When these people were faced with the land being too icy and covered in massive glaciers
these migrants were forced south into the modern day southern United States,
which is where their remains were eventually found (and these glaciers may be why we do not find their artifacts in northern parts of North America). Archaeologists were very comfortable with
this idea given the abundance of Clovis materials they found throughout North
America, and while they did not have additional evidence to back up their ideas
this notion of an ice-free corridor seemed the most solid and most supportable
and it came to be believed as truth.
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| Figure 2: Meadowcroft Rockshelter |
This all began to
change when other evidence slowly started to chip away at this idea. Evidence of earlier human occupations at several
North American sites, including Meadowcroft Rockshelter in Pennsylvania (Figure 2), Topper
Site in South Carolina, Cactus Hill in Virginia, Page-Ladsen in Florida,
and Paisley Cave in Oregon, as well as the site of Monte Verde in Chile, told a
different story, a much earlier one of human occupation of the New World. This made many scholars very uncomfortable,
particularly given the geographical distance among all these sites and what
knowledge they had regarding the climate of those periods, which was considered
glacial (meaning very icy) and too inhospitable for human occupation. Many archaeologists refuted these pieces of
evidence, claiming that they were not really human occupation sites or the
dates coming from the sites were incorrect.
Despite these criticisms, though, scholars kept working, believing that someday
they would truly know and understand when humans first settled the New World.
As luck would have it those scholars’ patience paid
off. With advances in paleogenetic
studies scholars were able to test biological remains of humans (and animals,
as applicable) to determine when and where the first human migrants may have
come from. Additionally, advances in
paleoclimatic studies allowed scholars to reconstruct what the environment may
have looked like in the past.
Paleogenetic studies demonstrated that human occupations came from the
Asian continent, which supported previous notions, but that these migrations
actually came much earlier than expected, with liberal estimates claiming 30,000
years earlier than originally thought (although conservative results demonstrate
migration occurring about 5,000 years earlier than originally estimated). Paleoclimatic studies further revealed that
an ice-free corridor either did not exist or that it was not hospitable enough
to allow for human migration to have occurred to support the notion that the Clovis
people were the original migrants to the New World.
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| Figure 3: Hypotheses pertaining to the Peopling of the New World |
Begrudgingly (for some), scholars began to admit that they
may have been too quick to conclude that an ice-free corridor was the only
means of coming to the New World. An
additional hypothesis that had originally been entertained although quickly
dismissed was now once again available to pursue. This hypothesis puts forward the idea that
human migration did not occur over land but by sea (Figure 3), and that early peoples
traveled along the coasts of the Americas to seek suitable places to land and
explore the continents. Unfortunately,
as it was then and remains today it is difficult to test this hypothesis fully
since the coast lines these early migrants would have originally settled are underwater
and the artifacts associated with their early sites most likely lost given the
poor preservation conditions of the oceanic waters. Despite this lack of evidence the strength of
the evidence regarding the lack of free and traversable land through the Bering
land bridge does demonstrate strong support for the coastal migration
model. Perhaps as new advancements in
technology and scientific analyses occur we may be able to further and more
fully explore the coastal migration model.
Until then, we will just have to wait and see.
References
Arnaiz-Villena, A.; C. Parga-Lozano; E. Moreno; C. Areces;
D. Rey; P. Gomez-Prieto. 2010. 2010. “The
Origin of Amerindians and the Peopling of the Americas According to HLA Genes:
Admixture with Asian and Pacific People.”
Current Genomics 11: 102-114.
Curry, Andrew.
2012. “Ancient Migration: Coming
to America.” Nature 485: 30-32.
Kamrani, Kambiz.
2008. “Peopling of the Americas:
Three Step Model for Colonizing the Americas.”
Blog Post. Anthropology.net
Kitchen, A., Miyamoto, M.M., Mulligan, C.J., Harpending, H.
(2008). A Three-Stage Colonization Model for the Peopling of the Americas. PLoS
ONE, 3(2), e1596
Klein, C. 2016. “New Study Refutes Theory of How Humans
Populated North America.” History in the
Headlines. History.com
No Author. No
Date. “Other Migration Theories – Bering
Land Bridge National Preserve.” Bering
Land Bridge National Preserve Alaska.
Government Website.
No Author. 2015. “The Peopling of the New World.” Archaeology
Magazine. Archaeological Institute
of America.
Schurr, T. 2000. “Mitochondrial DNA and the Peopling of the
New World.” American Scientist May-June
1-10.
Schurr, Theodore G.
2004. “The Peopling of the New
World: Perspectives from Molecular Anthropology.” Annual
Review of Anthropology. 33: 551-583.
