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The journey of man, told by bacteria Bacteria tell a lot of stories. In the story of the human migration, the Y-chromosome and mitochondrial DNA (mtDNA) play major roles. Where does microbiology step in? For one, there is evidence that mitochondria were once primitive bacterial cells. Or are descendants of bacteria. Some scientists even argue that mitochondria are bacteria and should be given their own taxonomy. The mtDNA and the Y-chromosome are what the group of Geneticist and National Geographic Explorer-in-Residence Spencer Wells analyzes to give us a clue on our past as a people. His research points to a Y-chromosomal Adam in Africa as the one who fathered all human beings alive today. Read on as Wells talks about his research and his own DNA. FEMS Focus: During your research, you said that we came from one single ancestor in Africa. Is this correct? Spencer Wells (SW): Well, we can trace back to a single individual who gave rise
Source: nationalgeographic.com
Spencer Wells is a geneticist and anthropologist, an Explorer-in-Residence at the National Geographic Society, and Frank H.T. Rhodes Class of ‘56 Professor at Cornell University, US. He obtained a Bachelor of Science in Biology from the University of Texas at Austin in 1988, and a Ph.D. in Biology from Harvard University in 1994. He was a postdoctoral fellow at Stanford University 1994-98, and a research fellow at Oxford University 1999-2000. Wells did his Ph.D. work under Richard Lewontin, and later his postdoctoral research with Luigi Luca Cavalli-Sforza and Sir Walter Bodmer. His work, which has helped to establish the critical role played
to all Y-chromosomes or the mtDNA types of today. They weren’t the only people alive at that point but they were the ones who were lucky enough to leave their lineage down to the present-day. by Central Asia in the peopling of the world, has been published in journals such as Science, American Journal of Human Genetics, and the Proceedings of the National Academy of Sciences. He wrote the book “The Journey of Man: A Genetic Odyssey” in 2002, which explains how genetic data has been used to trace human migrations over the past 50,000 years, when modern humans first migrated outside of Africa. Wells also wrote and presented the PBS/National Geographic documentary of the same name. By analyzing DNA from people in all regions of the world, Wells has concluded that all humans alive today descend from a single man who lived in Africa around 60,000 90,000 years ago, a man also known as Y-chromosomal Adam. Since 2005, Wells has headed The Genographic Project, undertaken by the National Geographic Society, IBM, and the Waitt Family Foundation, which aims to create a full picture of how our ancestors populated the planet by analyzing DNA samples from around the world. He also wrote the books “Deep Ancestry: Inside the Genographic Project” in 2006 and “Pandora’s Seed: The Unforeseen Cost of Civilization” in 2010. (source: Wikipedia)
From the Editorial Team In November last year, FEMS had the chance to have a one-on-one interview with famous geneticist and anthropologist Dr Spencer Wells of the National Geographic Society. We talked to him about the journey of man from Africa to all known parts of the world. Wells is the Director of the Genographic Project of the National Geographic Society. He started the project in 2005, collaborating with indigenous peoples with the hope to form the largest database of human genotypes in the world. At the moment, the Genographic team already has more than 200,000 samples of DNA in its possession, from people all over the world. All of these tell that all humans alive today, even those born and living on different continents, share a common ancestor who lived in Africa 60,000 years ago. This story is told by the Y-chromosome and mitochondrial DNA, genetic markers that point to our ancestors. What does this mean to microbiology? That is what this issue is all about! Tone Tønjum & Chared Verschuur Editors
What caused the migration of the human race? Why did we leave Africa? SW: It was probably a population expansion. We see evidence that the human population, after going through a bottleneck effect, whereas it was reduced in size, significantly, there might have been only 2 or 3,000 people alive if we go back to 70,000 years ago. We expanded back from that. We expanded in Africa and some people started to leave. So it’s probably, literally, an expanding population of like, some people beyond Asia and the Americas.