A University of Alberta archeologist’s new research may lead to rethinking how and when our ancestors left Africa to colonize the globe. It has a bearing on health because as people’s diets changed, so changed their bone structure, size of pelvis, ease of childbirth, ability to survive on available foods, and development of ancestral diets.
The new study traces humanity’s African ancestry in a new way that may mean the rewriting of the ‘out of Africa’ dates usually taught in schools. The new study is published in the latest issue of the journal Quaternary International. The study also is supported by the Social Sciences and Humanities Research Council of Canada and the Wenner-Gren Foundation.
When did our species begin to migrate from its birthplace?
A University of Alberta researcher and anthropology chair Pamela Willoughby’s explorations in the Iringa region of southern Tanzania yielded fossils and other evidence that records the beginnings of our own species, Homo sapiens. Her research, recently published in the journal Quaternary International, may be key to answering questions about early human occupation and the migration out of Africa about 60,000 to 50,000 years ago, which led to modern humans colonizing the globe.
From two sites, Mlambalasi and nearby Magubike, she and members of her team, the Iringa Region Archaeological Project, uncovered artifacts that outline continuous human occupation between modern times and at least 200,000 years ago, including during a late Ice Age period when a near extinction-level event, or “genetic bottleneck,” likely occurred.
Ecotourism focuses on archaeology, health, and prehistory
Now, Willoughby and her team are working with people in the region to develop this area for ecotourism, to assist the region economically and create incentives to protect its archeological history. “Some of these sites have signs that people were using them starting around 300,000 years ago. In fact, they’re still being used today,” she explained in the December 13, 2012 news release, Tracing humanity’s African ancestry may mean rewriting ‘out of Africa’ dates. “But the idea that you have such ancient human occupation preserved in some of these places is pretty remarkable.”
People lived in rock shelters more than 300,000 years ago, and the same places are inhabited today. Ancient artifacts reveal how intelligent the artisans really were at that time rather than what was previously thought happened much later.
Magubike: Home to a modern Stone Age family?
Willoughby says one of the fascinating things about Magubike is the presence of a large rock shelter with an intact overhanging roof. The excavations yielded unprecedented ancient artifacts and fossils from under this roof. Samples from the site date from the earliest stages of the middle Stone Age to the Iron Age. The earlier deposits include human teeth and artifacts such as animal bones, shells and thousands of flaked stone tools.
The Iron Age finds can be dated using radiocarbon, but the older deposits must go through more specialized processes, such as electron spin resonance, to determine their age. Other parts of the Magubike rock shelter, excavated in 2006 and 2008, include occupations from after the middle Stone Age. Taken together, this information could be crucial to tracking the evolutionary development of the inhabitants.
“What’s important about the whole sequence is that we may have a continuous record of human occupation,” explained Willoughby in the news release. “If we do—and we can prove it through these special dating techniques—then we have a place people lived in over the bottleneck.”
Rugged, hilly terrain may have been key to survival
The team made similar findings at Mlambalasi, about 20 kilometres from Magubike. Among the findings at this site was a fragmentary human skeleton that probably dates to the late Pleistocene Ice Age—after the out-of-Africa expansion but at the end of the bottleneck period. The bottleneck theory explains what geneticists have found by studying the mitochondrial DNA of living people—that all non-Africans are descended from one lineage of people who left Africa about 50,000 years ago.
Reconstructions of past environments through pollen and other archeological records in Iringa suggest that people abandoned the lowland, tropical and coastal areas during that period but remained in the highlands, where vegetation has remained mostly unchanged over the last 50,000 years. Those who moved to higher ground may have found what is likely one of the few places that facilitated their survival and forced their adaptation. Further testing will determine whether these findings point to a clearer link to our African ancestors—a find Willoughby says could put that region of Tanzania on many archeologists’ radar.
Most scientists have said that modern Homo Sapiens all have had African ancestry. “It was only about 20 years ago that people recognized that modern Homo sapiens actually had an African ancestry, and everyone was focused on looking at early Homo sapiens in Europe who appeared around 40,000 years ago,” she said. “But we now know that as far as back as around 200,000 years ago, Africa was inhabited by people who were already physically exactly like us today or really close to being the same as us. All of a sudden, it’s not Europe in this time period that’s really important, it’s Africa.”
Engaging community yields co-operation, opportunity
Along with its scientific significance, Willoughby’s work may be a linchpin to potential economic growth for the region. Since 2005, when a local cultural officer showed her the sites, she has been sharing information about her research with local citizens, schools and government—opening up opportunities for more research and co-operation. She keeps the region informed of the team’s findings through posters distributed around Iringa, and has asked for and accepted assistance from local scholars. Now the community is also looking for her help in establishing the historic sites as a tourist attraction that will benefit the region.
Willoughby says she feels fortunate to have the support of the Tanzanian people. She tells people it is a shared history she is uncovering, something she is honored to be able to do. “They’re telling me, ‘You’re putting Iringa on the map,'” she said according to the news release. “As long as they keep letting me work there, and keep letting the people working with me work there, we’ll be happy.”
Scientists also are examining what people ate before agriculture came to parts of Northern Europe. You may want to read the December 12, 2012 news article, “Chemical analysis reveals first cheese making in Northern Europe in the 6th millennium BC.” The study is published today in the latest issue of the journal Nature. The first unequivocal evidence that humans in prehistoric Northern Europe made cheese more than 7,000 years ago is described in research by an international team of scientists, led by the University of Bristol, UK.
The public is becoming more interested in the link between prehistoric and modern DNA regarding any health-related discoveries
More people are getting interested in genome research not only to focus on health risks but also to track down ancestry where the paper trail stops. The field is called DNA-driven genealogy. And the hottest area of research is tracing African genes in Europeans, some of which entered Europe during the ice age or at the end of it, around 11,000 years ago.
And in some areas of Southern Europe African genes entered the European gene pool about 72 generations ago or at the end of the Roman Empire, during the mini-ice age of 535 CE through the medieval era. Most southern Europeans and Middle Easterners have a few African genes. You also may find helpful the book, Tracing Your Baltic, Scandinavian, Eastern European, & Middle Eastern Ancestry Online.
Genetic testing companies usually focus on finding the European genes in African Americans, but few emphasize noting the number of African genes in people whose ancestors came from parts of Europe surrounding the Mediterranean and Black Sea areas or the areas where the Volga flows into the Caspian Sea.
Ever wonder why you have African genes, when you got them, and in what geographic locations if you’re of European ancestry? The archaeology media can clear up some questions on that theme. And the mainstream media reports on new DNA sequencing machines that analyze your entire genome for about $1,000.
The mainstream media eagerly covered the new Proton Semiconductor Sequencer from Ion Torrent Systems Inc., a new DNA sequencing machine and chip designed to sequence the entire human genome in about eight hours for $1,000, which was displayed at the Life Technologies Corp. booth at the 2012 International Consumer Electronics Show at the Las Vegas Convention Center January 11, 2012 in Las Vegas, Nevada.
The company claims the USD 149,000 machine is beneficial for research and clinical applications as it cuts the current time of about a week and cost of about USD 3,000 to sequence a genome. CES, the world’s largest annual consumer technology trade show, ran through January 13, 2012 and featured more than 3,100 exhibitors showing off their latest products and services to about 140,000 attendees.
Now a new study reveals when many people of European ancestry acquired some of their African genes that show up in DNA tests which reveal matrilineal ancestry of people alive today who may have inherited those genes around 11,000 years ago. That dates the migrations of peoples just at the ending of the last ice age. How far back does genealogy go when the paper trail stops? The mainstream media eagerly covers ancient DNA.
Check out the March 26, 2012 news release, based on a DNA study from Cold Spring Harbor Laboratory, “Genetic study unravels ancient links between African and European populations.” Also see the article published in the journal Popular Archaeology, March 2012, “Study Shows Mixing Between Prehistoric Populations of Europe and Africa.”
Researchers conclude from a recently completed study (published online on March 27, 2012 in the journal Genome Research) that genetic material was exchanged between Europe and Africa as far back as 11,000 years ago, or more. In fact, many family history and genealogy associations who are fascinated by DNA-driven genealogy when the paper trail stops, can now trace their hidden African genes to the Roman Empire or to other conquests. Intermarriage or mating between different groups of people happened.
Also, there were migrations from Africa to Europe from not just between 72 generations ago to the fall of the Roman Empire and to medieval times as well–but also from 11,000 years ago. Check out the study in the journal Genome Research, “Reconstructing ancient mitochondrial DNA links between Africa and Europe.”
Check your public library to see whether there are genealogy classes. It’s a great time for the media to cover DNA-driven genealogy where the paper trail stops and the DNA testing interest becomes more curious of where people lived during the ice age. Now there’s a chance to take a closer look at where matrilineal DNA traveled in migrations thousands of years ago.
You might bring up to various genealogists the subject of ancient migrations to those interested in local genealogy who enjoy tracing their deep ancestry back to the ice age. Some of the gene flow happened at the end of the last ice age, about 11,000 years ago when numerous Europeans and Africans chose their mates based on various migrations of peoples.
Think ancient migrations in a time long before countries had borders. In fact, the archaeology media notes that large numbers of people moved between Africa and Europe during recent and well-documented time periods such as the Roman Empire, the Arab conquest, and the slave trade, and genetic evidence of these migrations lives on in Europeans today.
And there were lots more migrations in ancient times before the Roman Empire. Yes, there certainly were more ancient migrations. In a study published online March 26, 2012 in the journal Genome Research, researchers present the first genetic evidence for prehistoric gene flow between Africa and Europe, dating back as far as 11,000 years ago.
To trace the evolution and ancestry of humans, scientists study the DNA sequence of the mitochondria, a specialized cellular structure that produces energy for the cell and carries genetic information that is separate from the rest of the genome that resides in the nucleus.
Whereas the nuclear genome is a mix of genetic information from both mother and father, the mitochondrial DNA (mtDNA) is passed directly from mother to child without any contribution of DNA from the father. But not everyone’s (matrilineal) mtDNA is exactly alike.
During long periods of time, small changes in matrilineal (mother to daughter -MtDNA) sequences have arisen in different populations
Geneticists can use these changes as markers that indicate the movements and migrations of humans in the past, and classify them into specific “haplogroups.” In the current study, an international team of researchers performed the largest analysis of complete mtDNA genomes belonging to haplogroup L (a lineage of sub-Saharan Africa origin) in Europe to date, aiming to untangle the history of genetic links between the two contents. By comparing the sequences of mtDNA genomes from various regions of Europe with mitochondrial genomes from around the world, they made a very surprising observation regarding when sub-Saharan lineages appeared in Europe.
“It was very surprising to find that more than 35 percent of the sub-Saharan lineages in Europe arrived during a period that ranged from more than 11,000 years ago to the Roman Empire times,” said Dr. Antonio Salas of the University of Santiago de Compostela and senior author of the study, according to the news release. The other 65% of European haplogroup L lineages arrived in more recent times.
The authors explain that these contacts likely connected sub-Saharan Africa to Europe not only via North Africa, but also directly by coastal routes. Salas said that it still remains unknown why there was genetic flow between the Africa and Europe in prehistoric times. But one possible scenario is that some bidirectional flow was promoted when the last glaciation pushed some Europeans southward, until the glacier receded and populations returned north.
So you have intermarriage or its equivalent due to Europe being covered by ice and glaciers and many people having to move south. About 8,000 years ago the Sahara was a green paradise of plants, animals, and food with plenty of water. Not like it is today or even 5,000 years ago when the Sahara dried up and peoples moved in all directions to find food, water, and mates. People migrated back and forth between Europe and Africa when the world of the south was greener and fertile with food, rivers, and rain.
In addition to tracing the genetic links of Africa and Europe back to prehistoric times, Salas expects that their work will also help those individuals who want to learn more about their own ancestry. “There is a growing interest in direct-to-consumer genetic testing, including those aimed to serve a public interested in reconstructing their ancestry,” Salas said in the news release. “Studies like the one presented here will help to unravel inferences made in these studies.”
Scientists from the University of Santiago de Compostela (Galicia, Spain), the University of Perugia (Perugia, Italy), the University of Pavia (Pavia, Italy), the Sorenson Molecular Genealogy Foundation (Salt Lake City, UT), the University of Oxford (Oxford, UK), and the National Institute of Toxicology and Forensic Science (Sevilla, Spain) contributed to this study.
The work was supported by the Ministry of Science and Innovation (Spain), the EUROTAST Project, and Italian Ministry of the University. About the article: The manuscript will published online ahead of print tomorrow on Tuesday, March 27, 2012. Its full citation is as follows: Cerezo M, Achilli A, Olivieri A, Perego UA, Gómez-Carballa A, Brisighelli F, Lancioni H, Woodward SR, López-Soto M, Carracedo Á, Capelli C, Torroni A, Salas A. See the study, “Reconstructing ancient mitochondrial DNA links between Africa and Europe. Genome Res doi: 10.1101/gr.134452.111.”
About Genome Research
Launched in 1995, Genome Research is an international, continuously published, peer-reviewed journal that focuses on research that provides novel insights into the genome biology of all organisms, including advances in genomic medicine. Among the topics considered by the journal are genome structure and function, comparative genomics, molecular evolution, genome-scale quantitative and population genetics, proteomics, epigenomics, and systems biology. The journal also features exciting gene discoveries and reports of cutting-edge computational biology and high-throughput methodologies.
About Cold Spring Harbor Laboratory Press
Cold Spring Harbor Laboratory is a private, nonprofit institution in New York that conducts research in cancer and other life sciences and has a variety of educational programs. Its Press, originating in 1933, is the largest of the Laboratory’s five education divisions and is a publisher of books, journals, and electronic media for scientists.
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