The genographic project confirms humans migrated out of Africa through Arabia

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1. The genographic project confirms humans migrated out of Africa through Arabia – November 2, 2011

2. Early human populations evolved separately for 100,000 years – April 24, 2008

3. Where did we come from, and how did we get to where we live today? – June 29, 2007

 

 

http://phys.org/news/2011-11-genographic-humans-migrated-africa-arabia.html#jCp

Through a new analytical method, IBM and the Genographic Project find new evidence to support southern route of human migration from Africa via the Bab-el-Mandeb Strait in Arabia before any movement heading north, and suggests a special role for south Asia in the “out of Africa” expansion of modern humans

The genographic project confirms humans migrated out of Africa through Arabia

November 2, 2011

Evolutionary history shows that human populations likely originated in Africa, and the Genographic Project, the most extensive survey of human population genetic data to date, suggests where they went next. A study by the Project finds that modern humans migrated out of Africa via a southern route through Arabia, rather than a northern route by way of Egypt. These findings will be highlighted today at a conference at the National Geographic Society.
National Geographic and IBM’s Genographic Project scientific consortium have developed a new analytical method that traces the relationship between genetic sequences from patterns of recombination – the process by which molecules of DNA are broken up and recombine to form new pairs. Ninety-nine percent of the human genome goes through this shuffling process as DNA is being transmitted from one generation to the next. These genomic regions have been largely unexplored to understand the history of human migration.

By looking at similarities in patterns of DNA recombination that have been passed on and in disparate populations, Genographic scientists confirm that African populations are the most diverse on Earth, and that the diversity of lineages outside of Africa is a subset of that found on the continent. The divergence of a common genetic history between populations showed that Eurasian groups were more similar to populations from southern India, than they were to those in Africa. This supports a southern route of migration from Africa via the Bab-el-Mandeb Strait in Arabia before any movement heading north, and suggests a special role for south Asia in the “” expansion of modern humans.

Ajay Royyuru, senior manager at IBM’s Computational Biology Center, said: “Over the past six years, we’ve had the opportunity to gather and analyze  around the world at a scale and level of detail that has never been done before.  When we started, our goal was to bring science expeditions into the modern era to further a deeper understanding of human roots and diversity. With evidence that the genetic diversity in southern India is closer to Africa than that of Europe, this suggests that other fields of research such as archaeology and anthropology should look for additional evidence on the migration route of early humans to further explore this theory.”

The new analytical method looks at recombinations of DNA chromosomes over time, which is one determinant of how new gene sequences are created in subsequent generations. Imagine a recombining chromosome as a deck of cards. When a pair of chromosomes is shuffled together, it creates combinations of DNA. This recombination process occurs through the generations.

Recombination contributes to genome diversity in 99% of the human genome. However, many believed it was impossible to map the recombinational history of DNA due to the complex, overlapping patterns created in every generation. Now, by applying detailed computational methods and powerful algorithms, scientists can provide new evidence on the size and history of ancient populations.

IBM researcher Laxmi Parida, who defined the new computational approach in a study published in Molecular Biology and Evolution, said: “Almost 99% of the genetic makeup of an individual are layers of genetic imprints of the individual’s many lineages. Our challenge was whether it was even feasible to tease apart these lineages to understand the commonalities. Through a determined approach of analytics and mathematical modeling, we undertook the intricate task of reconstructing the genetic history of a population. In doing so, we now have the tools to explore much more of the human genome.”

The Genographic Project continues to fill in the gaps of our knowledge of the history of humankind and unlock information from our genetic roots that not only impacts our personal stories, but can reveal new dimensions of civilizations, cultures and societies over the past tens of thousands of years.

“The application of new analytical methods, such as this study of recombinational diversity, highlights the strength of the Genographic Project’s approach.  Having assembled a tremendous resource in the form of our global sample collection and standardized database, we can begin to apply new methods of genetic analysis to provide greater insights into the migratory history of our species,” said Genographic Project Director Spencer Wells.

The recombination study highlights the initial six-year effort by the Genographic Project to create the most comprehensive survey of human genetic variation using DNA contributed by indigenous peoples and members of the general public, in order to map how the Earth was populated. Nearly 500,000 individuals have participated in the Project with field research conducted by 11 regional centers to advance the science and understanding of migratory genealogy. This database is one of the largest collections of  genetic information ever assembled and serves as an unprecedented resource for geneticists, historians and anthropologists.

The Genographic Project seeks to chart new knowledge about the migratory history of the human species and answer age-old questions surrounding the genetic diversity of humanity. The project is a nonprofit, multi-year, global research partnership of National Geographic and IBM with field support by the Waitt Family Foundation. At the core of the project is a global consortium of 11 regional scientific teams following an ethical and scientific framework and who are responsible for sample collection and analysis in their respective regions. The Project is open to members of the public to participate through purchasing a public participation kit from the Genographic Web site (www.nationalgeographic.com/genographic), where they can also choose to donate their genetic results to the expanding database. Sales of the kits help fund research and support a Legacy Fund for indigenous and traditional peoples’ community-led language revitalization and cultural projects.

 Explore further: Where did we come from, and how did we get to where we live today?

Provided by: IBM


 

http://phys.org/news/2008-04-early-human-populations-evolved-years.html#nRlv

Early human populations evolved separately for 100,000 years

April 24, 2008

A team of Genographic researchers and their collaborators have published the most extensive survey to date of African mitochondrial DNA (mtDNA). Over 600 complete mtDNA genomes from indigenous populations across the continent were analyzed by the scientists, led by Doron Behar, Genographic Associate Researcher, based at Rambam Medical Center, Haifa, and Saharon Rosset of IBM T.J. Watson Research Center, NY and Tel Aviv University.

Analyses of the extensive data presented in this study provide surprising insights into the early demographic history of human populations before they moved out of Africa, illustrating that these early human populations were small and isolated from each other for many tens of thousands of years.

MtDNA, inherited down the maternal line, was used to discover the age of the famous ‘mitochondrial Eve’ in 1987. This work has since been extended to show unequivocally that the most recent common female ancestor of everyone alive today was an African woman who lived in the past 200,000 years. Paleontology provides corroborating evidence that our species originated on this continent approximately 200,000 years ago.

The migrations after 60,000 years ago that led modern humans on their epic journeys to populate the world have been the primary focus of anthropological genetic research, but relatively little is known about the demographic history of our species over the previous 140,000 years in Africa. The current study returns the focus to Africa and in doing so refines our understanding of early modern Homo sapiens history.

Doron Behar, Rambam Medical Center, Haifa, said: “We see strong evidence of ancient population splits beginning as early as 150,000 years ago, probably giving rise to separate populations localized to Eastern and Southern Africa. It was only around 40,000 years ago that they became part of a single pan-African population, reunited after as much as 100,000 years apart.”

Recent paleoclimatological data suggests that Eastern Africa went through a series of massive droughts between 135,000-90,000 years ago. It is possible that this climatological shift contributed to the population splits. What is surprising is the length of time the populations were separate – as much as half of our entire history as a species.

Saharon Rosset, IBM T.J. Watson Research Center, NY and Tel Aviv University, said: “The analysis of such a massive dataset presents statistical and computational challenges as well as great opportunities for discovery of the events that shaped our history and genetic landscape. For example, we can see evidence of a population expansion period starting around 70,000 years ago, perhaps leading to the out of Africa dispersal shortly afterward.”

The timing of these events coincides with the onset of the Late Stone Age in Africa, a change in material culture that many archaeologists believe heralds the beginning of fully modern human behavior, including abstract thought and complex spoken language.

Previous studies have shown that while human populations had been quite small prior to the Late Stone Age, perhaps numbering fewer than 2,000 around 70,000 years ago, the expansion after this time led to the occupation of many previously uninhabited areas, including the world beyond Africa.

Dr. Spencer Wells, National Geographic Explorer-in-Residence and Director of the Genographic Project, said: “This new study released today illustrates the extraordinary power of genetics to reveal insights into some of the key events in our species’ history. Tiny bands of early humans, forced apart by harsh environmental conditions, coming back from the brink to reunite and populate the world. Truly an epic drama, written in our DNA.”

Paleontologist Meave Leakey, Genographic Advisory Board member, National Geographic Explorer in Residence and Research Professor, Stony Brook University, added: “Who would have thought that as recently as 70,000 years ago, extremes of climate had reduced our population to such small numbers that we were on the very edge of extinction.”

To view the publication in full: www.ajhg.org/AJHG/fulltext/S0002-9297(08)00255-3

Source: National Geographic Society


http://phys.org/news/2007-06-today.html#jCp

Where did we come from, and how did we get to where we live today?

June 29, 2007

In the first scientific publication from The Genographic Project, a five-year effort to understand the human journey, we see the first attempts to answer these age-old questions.

Reporting their experience of genotyping human mitochondrial DNA from the first 18 months of the project in the open-access journal PLoS Genetics, Doron Behar and colleagues describe the procedures used to generate, manage and analyze the genetic data from 78,590 public participants. They also provide the first anthropological insights in this unprecedented effort to map humanity’s genetic journey through the ages.

An ongoing debate in the field of human population genetics concerns the accurate classification of genetic lineages into distinct branches on the human family tree, known as haplogroups. The rigorous genotyping and quality assurance strategies of the work done through The Genographic Project allow classification of mitochondrial lineages with unprecedented accuracy.

This methodology is now being made publicly available along with the anonymous genetic data itself. As well as making available a periodically-updated database comprising all data donated by participants, the researchers make available the Nearest Neighbor haplogroup prediction tool.

Citation: Behar DM, Rosset S, Blue-Smith J, Balanovsky O, Tzur S, et al. (2007) The Genographic Project public participation mitochondrial DNA database. PLoS Genet 3(6): e104. doi:10.1371/journal.pgen.0030104
genetics.plosjournals.org/perlserv/?request=get-document&doi=10.1371/journal.pgen.0030104

Source: Public Library of Science

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