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Tuesday, May 13, 2014

Ground-breaking technique traces DNA direct to your ancestor's home 1,000 years ago

Date: May 1, 2014 

Source: University of Sheffield

Summary:

Tracing where your DNA was formed over 1,000 years ago is now possible, thanks to a revolutionary technique. The ground-breaking Geographic Population Structure tool works similarly to a satellite navigation system as it helps you to find your way home, but not the one you currently live in -- but rather your actual ancestor's home from 1,000 years ago.





[Click to enlarge image]


Visualization: World map with human genetic signatures overlaid.
Credit: Image courtesy of University of Sheffield



Tracing where your DNA was formed over 1,000 years ago is now possible, thanks to a revolutionary technique developed by a team of international scientists led by experts from the University of Sheffield.

The ground-breaking Geographic Population Structure (GPS) tool, created by Dr Eran Elhaik from the University of Sheffield's Department of Animal and Plant Sciences and Dr Tatiana Tatarinova from the University of Southern California, works similarly to a satellite navigation system as it helps you to find your way home, but not the one you currently live in -- but rather your actual ancestor's home from 1,000 years ago.

Previously, scientists have only been able to locate where your DNA was formed to within 700kms, which in Europe could be two countries away; however this pioneering technique has been 98 per cent successful in locating worldwide populations to their right geographic regions, and down to their village and island of origin.

The breakthrough of knowing where the gene pools that created your DNA were last mixed has massive implications for life-saving personalised medicine, advancing forensic science and for the study of populations whose ancestral origins are under debate, such as African Americans, Roma gypsies and European Jews.

Genetic admixture occurs when individuals from two or more previously separated populations begin interbreeding. This results in the creation of new gene pools representing a mixture of the founder gene pool.

Such processes are extremely common in history during migrations and invasions, for example, when the Vikings invaded Britain and Europe in the 11th Century and settled with locals some of them formed a new Viking-Anglo-Saxon gene pool, but some married other Vikings and maintained their original gene pool, allowing GPS to trace their Scandinavian origins.

Dr Eran Elhaik said: "If we think of our world as being made up of different colours of soup -- representing different populations -- it is easy to visualise how genetic admixture occurs. If a population from the blue soup region mixes with a population from the red soup region their off-springs would appear as a purple soup.

"The more genetic admixture that takes place, the more different colours of soup are introduced which makes it increasingly difficult to locate your DNA's ancestry using traditional tools like Spatial Ancestry analysis (SPA) which has an accuracy level of less than two per cent."

He added: "What we have discovered here at the University of Sheffield is a way to find not where you were born -- as you have that information on your passport -- but where your DNA was formed up to 1,000 years ago by modelling these admixture processes.

"What is remarkable is that, we can do this so accurately that we can locate the village where your ancestors lived hundreds and hundreds of years ago -- until now this has never been possible."

To demonstrate how accurate GPS predictions are, Dr Elhaik and his colleagues analysed data from 10 villages in Sardinia and over 20 islands in Oceania. The research published today in the journal Nature Communications shows that Dr Elhaik and his team were able to place a quarter of the residents in Sardinia directly to their home village and most of the remaining residents within 50km of their village. The results for Oceania were no less impressive with almost 90 per cent success of tracing islanders exactly to their island.

"This is a significant improvement compared to the alternative SPA tool that placed Oceanians in India," said Elhaik.

"In his third book, children's author L. Frank Baum revealed that Oz resided around Australia. It always troubled me that if I ever met anyone claiming to be from the wonderful world of Oz, I would like to be able to verify their origins and now we can!

"This technique also means that we can no longer easily classify people's ethnic identities with one single label. It is impossible for any of us to tick one box on a form such as White British or African as we are much complex models with our own unique identities. The notion of races is simply not plausible."

Tracing our ancestry is now a major social trend and genealogy is the number one hobby in America. An estimated one million people in the USA have already had their DNA genotyped. People can explore their DNA by simply taking a swab from inside their mouth and sending it to a company such as 23andme or ancestry.com for costs ranging from $99-$200.

Dr Elhaik's co-author, Dr Tatiana Tatarinova, developed a website making GPS accessible to the public.

"To help people find their roots, I developed a website that allows anyone who has had their DNA genotyped to upload their results and use GPS to find their ancestral home," said Dr Tatarinova, who is also an Associate Professor of Research Paediatrics at the Keck School of Medicine of the University of Southern California.

"We were surprised by the simplicity and precision of this method. People in a given geographical area are more likely to have similar genetics. When they also have genetic traits typically found in other, distant regions, the geographical origin of those traits is generally the closest location where those traits can be found."

According to the researchers, in ethnically-diverse regions like the UK or US, where many people know only a few generations of their descendants, this kind of screening has huge, important medical implications.

Discovery of a certain genotype might indicate the potential for a genetic disease and suggest that diagnostic testing be done. Also, as scientists learn more about personalized medicine, there is evidence that specific genotypes respond differently to medications -- making this information potentially useful when selecting the most effective therapy and appropriate dosage. The investigators are currently designing a study to correlate pharmacokinetics -- the time course of drug metabolism -- with genotype.

Video: https://www.youtube.com/watch?v=Aap-s1kle4Q


Story Source:

The above story is based on materials provided by University of Sheffield. Note: Materials may be edited for content and length.


Journal Reference: 

Eran Elhaik, Tatiana Tatarinova, Dmitri Chebotarev, Ignazio S. Piras, Carla Maria Calò, Antonella De Montis, Manuela Atzori, Monica Marini, Sergio Tofanelli, Paolo Francalacci, Luca Pagani, Chris Tyler-Smith, Yali Xue, Francesco Cucca, Theodore G. Schurr, Jill B. Gaieski, Carlalynne Melendez, Miguel G. Vilar, Amanda C. Owings, Rocío Gómez, Ricardo Fujita, Fabrício R. Santos, David Comas, Oleg Balanovsky, Elena Balanovska, Pierre Zalloua, Himla Soodyall, Ramasamy Pitchappan, ArunKumar GaneshPrasad, Michael Hammer, Lisa Matisoo-Smith, R. Spencer Wells, Oscar Acosta, Syama Adhikarla, Christina J. Adler, Jaume Bertranpetit, Andrew C. Clarke, Alan Cooper, Clio S. I. Der Sarkissian, Wolfgang Haak, Marc Haber, Li Jin, Matthew E. Kaplan, Hui Li, Shilin Li, Begoña Martínez-Cruz, Nirav C. Merchant, John R. Mitchell, Laxmi Parida, Daniel E. Platt, Lluis Quintana-Murci, Colin Renfrew, Daniela R. Lacerda, Ajay K. Royyuru, Jose Raul Sandoval, Arun Varatharajan Santhakumari, David F. Soria Hernanz, Pandikumar Swamikrishnan, Janet S. Ziegle. Geographic population structure analysis of worldwide human populations infers their biogeographical origins. Nature Communications, 2014; 5 DOI: 10.1038/ncomms4513


Cite This Page:

University of Sheffield. "Ground-breaking technique traces DNA direct to your ancestor's home 1,000 years ago." ScienceDaily. ScienceDaily, 1 May 2014. <www.sciencedaily.com/releases/2014/04/140430192745.htm>.

Monday, May 12, 2014

Sustainability needs link between theory, practice in education

Wonderful article looking at the challenges of sustainability education.

Date:
May 9, 2014
Source:
Wageningen University and Research Centre
Summary
How can you ensure that people do not only spend time thinking about important global issues like climate change or world food supplies, but also roll up their sleeves and do something about them? Researchers think that the education sector holds the key. Teaching processes around the world could be given more influence and meaning by making pure science subjects, such as biology and physics, complementary to lessons in nature, environment and sustainability.


How can you ensure that people do not only spend time thinking about important global issues like climate change or world food supplies, but also roll up their sleeves and do something about them? Four researchers, including Professor Arjen Wals from Wageningen University, think that the education sector holds the key. Teaching processes around the world could be given more influence and meaning by making pure science subjects, such as biology and physics, complementary to lessons in nature, environment and sustainability. Their article on this new approach to teaching, which is based on citizen science, is published in the 9 May edition of Science.

Throughout the world, 'pure' science subjects such as physics, chemistry, biology, maths, geography and general natural sciences, which traditionally aim to build up knowledge and understanding, are seen separately from subjects such as nature and the environment, which together with the latest branch 'sustainability education' take a more practical approach. Although this certainly makes scholars aware of the current condition of our planet, their lack of practical perspective evokes a sense of powerlessness. For example, what can you do to prevent or respond adequately to forthcoming climate shifts? Affinity with politics, society and the economy are essential in this respect. Conversely, education in nature, the environment and sustainability (aka 'environmental education') does not equip scholars with the scientific insight they need to back up their proposed remedies.

Convergence

When taught separately, natural sciences and environmental education give a disjointed answer to society's demand for a truly sustainable society. "It's time these two schools converged," says Arjen Wals, Professor of Social Learning and Sustainable Development at Wageningen University. "If we cannot create a firm link between these two educational areas, scientific education is in jeopardy of becoming purely a vehicle for enhancing the innovative and competitive potential of a country's economy," he says. "At the same time, without a firm link with the sciences, environmental education will never be able to find a responsible and realistic way of dealing with the contradictions and uncertainties that are raised in the scientific debate surrounding questions of sustainability."

The authors of the article in Science give a number of examples of environmental education, which cover the area where science meets society. Among them is the American concept of Edible School Gardens, whereby schoolchildren grow their own food in an educational garden while simultaneously learning about the things they grow in science lessons. The Dutch version is known as Groene schoolpleinen ('green school grounds'). Another good example is YardMap, based on IT and citizen science. Citizens, both young and old, analyze biodiversity in their own neighborhood by means of digital photos, special apps and Google Maps. The aim is to identify the areas with the greatest potential for boosting biodiversity. Action plans designed to ensure that the YardMaps are kept fully up-to-date are drawn up and implemented on the basis of studies and in consultation with scientists and local partners (including the municipal authority, garden centers and an NGO). The various YardMaps are linked via social media. The Dutch Natuurkalender works in much the same way.

Creating closer ties between citizen science, scientific education and environmental education will help citizens and scientists to take a meaningful and practical approach to the pursuit of sustainability. Wals: "It's not just about linking up the content; it involves developing new competencies such as dealing with complexity, uncertainty and confusion, and devising and implementing meaningful local solutions." This method of learning may also help to restore the damage to public confidence in science. The government will have to put more effort into stimulating and supporting the 'hybrid teaching environments' that blur the boundaries between science and society, school and neighborhood, local and global, and shift the emphasis to the wellbeing of mankind and the planet.

Transition

Calls for transition and another way of thinking are becoming more urgent, says Professor Wals: "At the end of the day, the climate problem is as much in between our ears, as it is between the North and South Poles." He backs this up with a remarkable conclusion: to his mind, the role of education and citizen involvement has been seriously underemphasized in the climate debate. In fact he wonders if we will ever be able to bring about a transition without committed, critical and competent citizens, who aspire to values that are not purely based on the material side of their existence but also on care for fellow human beings and, indeed, other species, here and elsewhere, now and in the future.


Story Source:
The above story is based on materials provided by Wageningen University and Research Centre. Note: Materials may be edited for content and length.



Journal Reference:
A. E. J. Wals, M. Brody, J. Dillon, R. B. Stevenson. Convergence Between Science and Environmental Education. Science, 2014; 344 (6184): 583 DOI: 10.1126/science.1250515