A growing number of archaeological finds suggest the Americas were settled earlier than thought, and by at least two different groups of people. What's startling is that the oldest human remains look like Australian Aborigines.
Who were the first people to set foot in the Americas? For a long time, the answer to this question seemed as sharply defined as the end of the fluted hunting tools known as 'Clovis points' found in scattered sites across North America: humans colonised the Americas rather late in the history of human expansion.
After scampering about in trees for a few million years, anatomically modern humans emerged in Africa and promptly began migrating to the four corners of the world. The earliest ancestors expanded throughout Asia, arriving in Australia at least 50,000 years ago, Europe at least 45,000 years ago and western Melanesia at least 40,000 years ago. There, the eastward expansion came to a halt. The last two habitable continents remained out of reach across the wide open body of water we now call the Pacific Ocean.
Eventually, one group of humans, with distinctive Mongoloid features, around Northern Asia mastered the art of hunting mega fauna. During the last Ice Age, when the world's water was locked up in massive ice sheets and glaciers, the Bering Strait was drained to reveal the continental shelf between Siberia and Alaska. The ancestors of today's Native Americans followed the herds of mammoths, long-horn bison and horses on the final eastward expansion, arriving in the New World by about 11,200 years ago.
According to this traditional view, the big-game hunters of Mongoloid appearance continued their expansion southward, through an interior ice-free path formed by the retreating glaciers. When they reached what is today the western United States, they flourished. Their success is marked by the prolific stone hunting tools first found near the town of Clovis, New Mexico, in the 1930s. In less than 1,000 years, the Clovis people (as they're known) trekked from Alaska to the tip of South America, eventually founding all the indigenous populations of North and South America.
Modern research has suggested as a consequence of other archaeological evidence becoming available from ancient sites that predate the Clovis culture that other races initially settled along the west coast of the Americas. Indeed, later research has indicated that the people who left Africa in the initial mass colonisation event were not altered by the Pacific Ocean.
One example of this earlier settlement has been found from an ancient "Luzia woman" whose skeleton is held in the University of Sao Paolo, Brazil. This skeleton has a very projected space, with her chin sitting out further than her forehead. She has a long, narrow brain case, measured from the eyes to the back of the skull, a low nose and low orbits - the space where the eyes sit. Indeed, Luzia looks very much like an Australian aboriginal.
Luzia, however, was discovered a world away, thirteen metres underground in Central Brazil, in one of the many mine stone rock shelters that make up an extensive system called Lapa Vermelha. In the mid 1990s the bones were analysed and it was concluded that they all belonged to a single female who was named "Luzia" as a homage to a specimen of Australopithicus afarensis dubbed Lucy, one of the early hominids in Africa who walked on two legs instead of four. Exact carbon dating could not be performed on Luzia who died when she was in her early 20s because researchers did not have the protein collagen necessary to date human remains. However, the layers of the rock shelter in which she was found indicate that she lived between 11,000 and 11,500 years ago. Scientists have indicated that Luzia may well be the oldest human skeleton in the Americas.
Certainly Luzia is not alone. Several skeletal remains have since been analysed in seven archaeological sites from the far north as Florida in the USA and as far south as Chile. They all look most similar to sub-Saharan Africans, Australian Aborigines and some of the original populations of the Pacific Islands. What they don't look like is native Americans or East Asians. While Luzia may be the oldest human remains discovered in the Americas, she was not the first to be found.
As early as 1989, some scientists proposed the existence of a non-mongoloid migration into the Americas that pre-dated the Clovis culture. An examination of 38 skeletons from three sites in Brazil and Colombia dated from 6000 to 12,000 years ago. The research suggested a clear biological affinity between the early South Americans and the South Pacific population. This association suggested the conclusion that the Americas were occupied before the spreading of the classical mongoloid morphology in Asia. This conclusion was further strengthened by the analysis of a further 81 skeletons from Lagoa Santa.
Certainly, the conclusion raises the question of how on earth did a group of people who look like Australian Aborigines get all the way to Brazil at least 12,000 years ago. Research has shown that these people were in China about 20,000 years ago and that the mongoloid population that you see in Asia today is more recent. One possibility is that Luzia's "American Aborigines" shared a last common ancestor with the Australian aborigines in Southeast Asia with one group setting to the great southern land (Australia), arriving around 50,000 years ago. The other group wound their way through Asia and eventually made their way to Siberia, across the Bering Strait to Alaska. They did this thousands of years before the Clovis people.
Research is still being undertaken as to the manner in which these early people crossed the Bering Strait with some archaeologists suggesting that North and South America were colonized by boats. At this time, archaeologists continued to piece together theories based on circumstantial evidence such as remains while geneticists examine population today and look for clues to their paths in mutations in the human DNA build-up in order to pinpoint when these mutations first appeared. Then, using particular mutations as markers, they can then trace the journey of different peoples back in time. In the case of Luzia, and her relative bones, DNA analysis is no easy task because the bones are so old that the DNA is highly degraded and contaminated with other human DNA, bacteria and viruses. While Brazil may have been too hot and wet to provide a good DNA sample, this problem does not exist at the southern tip of the continent.
As a result of the above, researchers are working from samples from the southern region using new sequencing technology that can directly read the ancient pieces of DNA. It is this research that will conclusively prove who reached the New World first. Could it really have been the common ancestor of the Australian Aborigines or even the Australian Aborigines themselves? Did they take the voyage across the vast Pacific in flimsy craft or did they brave the southern ocean to reach the tip of South America? Alternatively, did they perverse the distances up to Siberia and across the Bering Strait and all the way to southernmost Chile?
This Web site:
Australia - Aboriginal - America
will be updated further when the results of ongoing research become available.