Physical Anthropology and Archaeology
Chapter 8 Hunting, Fishing, Sailing, and Sledding: The Spread of Humanity Worldwide
In This Chapter
Looking at some early colonization theories
Understanding the role of artifacts and adaptation in colonization
Navigating like prehistoric humans
Where do you come from? I mean way back, centuries ago? Your family names may help a bit, but most people can only point at a vague blob on a map, a country that may not even exist anymore. But how about the people who came from there?
Where did they come from? And how did they get there? Ultimately, everyone’s roots reach back thousands of years to Africa; Chapter 7 tells you that. This chapter tells you about what happened next: how humans (officially, anatomically modern Homo sapiens sapiens, or AMHss) adapted to the multitude of new ecosystems they encountered, how they survived them by inventing everything from igloos to dogsleds and sailing canoes to fishing nets, and a little about how and when they migrated into and colonized such forbidding places as the islands of the open Pacific and the Arctic
Migration and Survival: The Decoupling of Behavior from Biology
Pay attention here; I’m giving a quiz later. Just kidding. But really, this is one of the main lessons of anthropology and of this entire book!
The first thing to keep in mind is that for a long time — from at least 100,000
people who moved from place to place to gather and hunt for their daily food and water. Sedentary farm life just wasn’t an option until farming was invented around 10,000 years ago. And even then, not everyone took up farming; for thousands of years, many people continued to forage, trekking thousands of miles across the Arctic or voyaging on the open Pacific.
But why? Prehistoric humans moved for lots of reasons, including
Resource exploration: Foragers are always interested in what other resources may be available just out of sight.
Social fission: Some foragers move to get away from neighbors with whom they have bad blood; others travel to disperse a population that’s getting too high for the resources in the immediate environment to support.
Incidental migration: Foragers often migrate in pursuit of their prey animals — like herds of mammoth — who are also moving across landscapes to take advantage of new resources like expanding grassland in a changing ecosystem.
For these reasons (and others people may never know), humanity spread far and wide after 100,000 years ago.
Human migration required adaptation to survive in new environments. As a noun, an adaptation is an object that allows survival in that new environment, such as warm fur clothing for a cold environment or a new kind of sail for your sailing vessel. All other animals adapt unconsciously and with their bodies (which either do or do not have traits that allow survival in new environments); on the other hand, human bodies are biologically frail and could hardly survive the Arctic or the Sahara.
But humans have invented ways to live in both places, for thousands of years and in fine health; humanity has invented adaptations to places that our biology couldn’t withstand. In fact, this is one of the most distinctive characteristics about humanity: It proactively chooses to make and invent new adaptations. Humanity, then, adapts not only with its body but also with its inventions, be they artifacts or social customs. This is one of the most important
lessons anthropology has learned about humanity: For good or ill, humanity has evolved ways of adapting that have decoupled behavior from biology.
The rest of this chapter is really here to give you some examples of the diversity of these two main types of fascinating adaptations:
Artifacts: Physical adaptations, like a warm coat or a sun-deflecting hat
Behaviors: Cultural adaptations, like the practice of committing suicide when one can no longer support the foraging group and is a burden on the already-meager resources
One way to begin imagining the staggering history of early human global migration is to consider the environments people were moving into and what material and social adaptations could have made those new environments survivable. You can do this fascinating thought-exercise by considering the variety of environments humanity was exploring and adapting to in Figure 8-1, which generally sketches out the various dispersals of humanity around the world after about 100,000 years ago. The routes shown are pretty general, but keep in mind some major barriers, such as the Himalayan mountain chain. A couple of other things to keep in mind: By 100,000 years ago, the continents were in their present positions, so you don’t need to wonder about South America shifting around or anything. Also, during ice ages ocean water was locked up in glaciers, so water levels were about 300 feet lower than they are today, thus making coastlines extend out farther. If you need a visual of this extension, you can check out sahultime.monash.edu.au/explore.html for a series of maps showing these changes in the coastlines of Australia.
Considering the principles of why and how humanity emerged from Africa, take a closer look at some of our species’ thrillingly ingenious methods of survival in this epic of epics: the colonization of the globe by our prehistoric ancestors.
The Colonization of Australasia
The initial colonization of Australia is a mind-boggling odyssey of hunting and foraging among the island chains of Southeast Asia toward the open ocean leading to Australia. Somehow, people invented some kind of watercraft and used them to hop from island to island, until they reached The Big One: Australia itself.
Then, they trekked into the desert interior of this immense continent.
The mysteries of Australian colonization
Something’s up Down Under. When humanity first came to the continent of Australia is one of the great mysteries of archaeology. Many sites date earlier than 30,000 years old, but none seem to be definitively dateable because the strata have been disturbed a little or the method being used to date the site is at the edge of its useful range — something’s always a little off. Still, anthropologists are confident that Australia was colonized well over 40,000 years ago. Main finds that make that clear:
The Lake Mungo skeleton, found in 1974, has recently been redated to just over 60,000 years ago.
In 2002, rock art at the Nauwalabila I site in Northern Australia was dated to more than 50,000 years ago.
Rock art at the Carpenter’s Gap site is securely dated to about 40,000 years ago.
Whatever the ambiguities with some of the data from these sites, they all point in the same direction: to occupation of Australia at least by 40,000 years ago, and maybe much earlier. How much earlier? One claim, published in 1996, was for a site dated to more than 175,000 years ago. That would be even earlier than AMHss, and few people — myself included — buy it. I want much better evidence (and multiple lines of it) all pointing in the same direction before I accept such an early date.
Only 50 years ago, many thought Australia was colonized no earlier than 8,700 years ago, but today data indicate it was colonized at least three times earlier than that. This is a pattern in archaeology; dates for the earliest circumstance of something — like the colonization of a region or the invention of an artifact — constantly get pushed back as new sites surface. This pattern doesn’t mean that archaeology is rudderless and constantly rewriting its books, however.
What it does do, like any good science, is update what it knows and move on. In this case, the update is pretty major, but it’s still just an update, not a condemnation of all archaeology.
What anthropologists know for sure
Despite the mysteries of Australian colonization, a few facts are certain:
Australia was colonized by 40,000 years ago.
Australia was colonized by AMHss, as evidenced by their skeletons.
Australia was colonized by behaviorally modern Homo sapiens sapiens, as evidenced by their cave art, which indicates symbolism.
Reconstruction of sea levels reveals that at the time Australia was colonized, it was already an island; therefore, the colonizers must have used some
(though that doesn’t mean they don’t exist), but water crossings beyond the sight of land would have been necessary, so archaeologists infer that early Australians used watercraft.
Another Grand Exploration: The Colonization of the New World
Yet another wild, hair-raising, and unlikely story of prehistoric migration and colonization is that of the colonization of the New World (North and South America). Combined, this region opened up more than 40 million square kilometers (more than 15 million square miles) to humanity, who swiftly spread to inhabit every conceivable ecological niche — the grassy Great Plains, the icy Arctic, the windswept coast of Peru, the steaming jungles of Central America, the hardwood forests of Appalachia, the Mississippi basin, the blustery Pacific Northwest, the arid Great Basin, and just about everywhere in-between. How people survived to become today’s Native Americans is a staggering tale this section can only begin to cover; however, it can give you an idea of what was involved.
Dueling hypotheses: A couple of migration theories
The real mysteries about the colonization of the Americas lie in the timing and circumstances of the earliest occupants. At one time, a book like this would have delved deeply into the question of where the first Americans came from, but today that mystery is solved. Dental, genetic, linguistic, and archaeological data all clearly link the native peoples of the Americas with the native peoples of Northeast Asia: specifically, Siberia.
Although this link was first proposed as early as the 16th century, as people made the obvious connections between native people of these areas, the many lines of evidence have come together only in the last century to support this common-sense notion. A recent widely published hypothesis — that Native Americans came across the sea ice from Europe (about 18,000 years ago) — relies on the scantest evidence and isn’t convincing any archaeologists I know or know of. Right now, all lines of evidence point to Northeast Asia. From there, humans moved toward North America by crossing a land bridge (between eastern Siberia
and Western Alaska) called Beringia. During the ice ages (which didn’t end until about 10,000 years ago), Beringia was an
expansive vegetated tundra grazed by herds of megafauna (large animals), such as the wooly mammoth. After crossing into Alaska, however, the question is where he colonists went next, as we’ll see in the following sections.
Ice-Free Corridor hypothesis
The Ice-Free Corridor hypothesis suggests that migrants entered the Americas between two great ice sheets that covered Canada until about 12,000 years ago. The Ice-Free Corridor model proposes that as the ice sheets melted due to the end of the ice age, a broad corridor opened between them, allowing plants to colonize this strip of land connecting today’s western Canada with the United States’ Great Plains. Large grazing animals such as bison and mammoths migrated south to feed upon these plants, and bands of human foragers followed.
According to some geographers and glaciologists, the big problem with the Ice-Free Corridor hypothesis is that so much water would have poured off the mile-thick ice sheets that the newly exposed ground between them couldn’t have stabilized quickly enough for the plants to take root, let alone support grazers.
Rather, the corridor would have been a no man’s land of glacial outwash, blasted by roaring rivers that changed course unpredictably. These folks maintain that nobody came through the corridor until many thousands of years after the ice melted, the water drained off, soil stabilized, and plants took root.
The Ice-Free Corridor model is usually proposed by the Clovis-First theorists, who believe that the first people into the Americas bore distinctive stone tools called Clovis Points. For a long time, this theory was generally accepted among archaeologists, but in the last two decades new data (see the following two sections) have strongly suggested that Clovis wasn’t first at all.
Coastal migration hypothesis
In contrast to the Ice-Free Corridor hypothesis, the coastal migration hypothesis proposes that migrants traveled ever southward down the coasts of Alaska, British Columbia, Washington, Oregon, and then California. At least at first; eventually, they also headed east further into the North American continent
by following the big rivers that empty into the Pacific from north to south: the Fraser (near Vancouver, British Columbia), the Columbia, the Sacramento (at San Francisco Bay), and others.
The first evidence for this hypothesis is a coastal route that many people used to rule out simply because they thought the great ice sheets extended far out to sea, creating a 300-foot ice-wall barrier that no humans could migrate along and survive. But recently, glacial refugia (islands that weren’t iced over) have come to light; scientists have confirmed these islands were actually forested, serving as refuges from the worst conditions. Alaska’s On Your Knees Cave (yes, that’s its real name) contained bear remains more than 15,000 years old; people argue that if the refuges could have supported bears, they could have supported equally omnivorous humans.
Although the tide of opinion currently favors the coastal migration hypothesis, keep in mind that it’s going to be tough to prove. When the ice sheets melted by 10,000 years ago, the runoff poured into the oceans, raising the sea level. Today the water is 300 feet deeper than it was when the coastal migrants presumably made their way south, so remains of their campsites are underwater.
Diving more than about 100 feet starts to get really complicated, so SCUBA survey is a tough proposition.
Just the facts, ma’am
I personally strongly favor the coastal migration hypothesis, but whatever the case, people were definitely in the Americas well over 10,000 years ago. Three archaeological sites make that clear:
The Monte Verde site in Chile is securely radiocarbon dated to more than 12,000 years ago. (See Chapter 5 for more on radiocarbon dating.)
Idaho’s Buhl skeleton is securely dated to 10,600 years ago.
The Kennewick Man is securely dated to 9,400 years ago; though this date isn’t actually more than 10,000 years ago, it’s pointing in the right direction. If people reached southern Washington by 9,400 years ago, you can pretty safely bet they were into North America just 600 years before that. (See the nearby sidebar “The Kennewick controversy.”)
And the story keeps changing. A site in Oregon currently shows radiocarbon dates for human occupation spanning back to 14,300 years ago. If the dates pan out and the research holds up under the thorough scrutiny that’s the hallmark of good science, this will be the oldest well-accepted date for human occupation in North or South America. This find is exciting to say the least, but as anthropologists we’ll will have to wait for all the evidence to be reviewed by the scientific method before we begin rewriting the textbooks.
The Voyage of Ru and Hina: The Colonization of the Pacific
Between 3,000 years ago and 1,500 years ago, the ancient Polynesians voyaged throughout the Pacific, building a habit of exploration typified by the legend of the exploring siblings Ru and Hina (who, having discovered every scrap of land in the Pacific, looked to the moon, saw a new place to tread, and built a magical ship to take them there). The ancient Polynesians eventually colonized Tahiti, Easter Island, New Zealand, and Hawaii; just like everywhere else, this colonization effort was a masterpiece of adaptation. These peoples carefully shaped both technologies and cultures to make exploration and survival in the Pacific possible. The technologies included the double-hulled voyaging canoes
and special methods of navigation (see more on this in the following section). The following section describes some more examples of human adaptation to the Pacific.
In 1947, the Norwegian adventurer Thor Heyerdahl and his crew drifted from Peru to Polynesia on a 40-foot log raft named Kon-Tiki to show that Polynesia could have been colonized by ancient South Americans. Though Heyerdahl’s feat was a bold adventure, no solid evidence suggests he was right;
linguistic, DNA, and archaeological evidence all clearly show that the colonists of the Pacific originated in Southeast Asia, not South America.
The tools of the explorers
The earliest explorers of the Pacific were inventive people determined to survive their explorations. They didn’t sail haphazardly or simply drift with the currents;
on the contrary, they planned their expeditions and carried artifacts to enable them to survive at sea and start a new life after they found land. Among their inventions were
Double-hulled voyaging canoes up to 60 feet long and carrying up to 100 people
Pottery used to contain and cook foods on board
Stone adzes, tools used to clear land for horticulture when the explorers found land
Fish hooks made from shell and used to catch fish while underway The society of the explorers
The Pacific explorers also invented cultural traditions to survive, which were just as important as any artifact. These traditions included
An acceptance of risk: Although the explorers felt that life was precious, they acknowledged that bravery was often necessary at sea and that life could be unpredictable.
A mythology of divine intervention: This system reassured voyagers that the gods did sometimes take pity, that every storm would eventually end, and that life would be good when they found land.
A glorification of exploration: The greatest glory went to those who explored and found new land in which to raise the next generation. The tale of Ru and Hina exemplifies this belief.
Chapter 9 Old, Old McDonald: The Origins of Farming