Navigation Links
Reading history through genetics

New York, NYDecember 5, 2012Computer scientists at Columbia's School of Engineering and Applied Science have published a study in the November 2012 issue of The American Journal of Human Genetics (AJHG) that demonstrates a new approach used to analyze genetic data to learn more about the history of populations. The authors are the first to develop a method that can describe in detail events in recent history, over the past 2,000 years. They demonstrate this method in two populations, the Ashkenazi Jews and the Masai people of Kenya, who represent two kinds of histories and relationships with neighboring populations: one that remained isolated from surrounding groups, and one that grew from frequent cross-migration across nearby villages.

"Through this work, we've been able to recover very recent and refined demographic history, within the last few centuries, in contrast to previous methods that could only paint broad brushstrokes of the much deeper past, many thousands of years ago," says Computer Science Associate Professor Itsik Pe'er, who led the research. "This means that we can now use genetics as an objective source of information regarding history, as opposed to subjective written texts."

Pe'er's group uses computational genetics to develop methods to analyze DNA sequence variants. Understanding the history of a population, knowing which populations had a shared origin and when, which groups have been isolated for a long time, or resulted from admixture of multiple original groups, and being able to fully characterize their genetics is, he explains, "essential in paving the way for personalized medicine."

For this study, the team developed the mathematical framework and software tools to describe and analyze the histories of the two populations and discovered that, for instance, Ashkenazi Jews are descendants of a small numberin the hundredsof individuals from the late medieval times, and since then have remained genetically isolated while their population has expanded rapidly to several millions today.

"Knowing that the Ashkenazi population has expanded so recently from a very small number has practical implications," notes Pe'er. "If we can obtain data on only a few hundreds of individuals from this population, a perfectly feasible task in today's technology, we will have effectively collected the genomes of millions of current Ashkenazim." He and his team are now doing just that, and have already begun to analyze a first group of about 150 Ashkenazi genomes.

The genetic data of the Masai, a semi-nomadic people, indicates the village-by-village structure of their population. Unlike the isolated Ashkenazi group, the Masai live in small villages but regularly interact and intermarry across village boundaries. The ancestors of each village therefore typically come from many different places, and a single village hosts an effective gene pool that is much larger than the village itself.

Previous work in population genetics was focused on mutations that occurred very long ago, say the researchers, and therefore able to only describe population changes that occurred at that timescale, typically before the agricultural revolution. Pe'er's research has changed that, enabling scientists to learn more about recent changes in populations and start to figure out, for instance, how to pinpoint severe mutations in personal genomes of specific individualsmutations that are more likely to be associated with disease.

"This is a thrilling time to be working in computational genetics," adds Pe'er, citing the speed in which data acquisition has been accelerating; much faster than the ability of computing hardware to process such data. "While the deluge of big data has forced us to develop better algorithms to analyze them, it has also rewarded us with unprecedented levels of understanding."


Contact: Holly Evarts
Columbia University

Related biology news :

1. MindSpec launches online Autism Reading Room
2. New model of disease contagion ranks US airports in terms of their spreading influence
3. Flightless molecule may prevent cancer from spreading from 1 tissue to another
4. Frequent traveller: Dysentery-causing bacteria spreading from Europe to Australia
5. Brain-wave-reading robot might help stroke patients
6. New book on stereology by Mark West is essential reading for neurobiologists
7. Joint UT study: Reading food labels helps shoppers stay thinner
8. Scientists trace evolutionary history of what mammals eat
9. Family history of liver cancer increases risk of developing the disease
10. Earth history and evolution
11. New coelacanth find rewrites history of the ancient fish
Post Your Comments:
(Date:5/9/2016)... Elevay is currently known as ... for high net worth professionals seeking travel for work ... world, there is still no substitute for a face-to-face ... your deal with a firm handshake. This is why ... of citizenship via investment programs like those offered by ...
(Date:4/26/2016)... -- Research and Markets has announced the ...  report to their offering.  , ,     (Logo: ... forecast the global multimodal biometrics market to grow ... 2016-2020.  Multimodal biometrics is being implemented ... healthcare, BFSI, transportation, automotive, and government for controlling ...
(Date:4/13/2016)... -- IMPOWER physicians supporting Medicaid patients in Central ... in telehealth thanks to a new partnership with higi. ... patients can routinely track key health measurements, such as ... when they opt in, share them with IMPOWER clinicians ... retail location at no cost. By leveraging this data, ...
Breaking Biology News(10 mins):
(Date:6/23/2016)... Cancer Foundation (PCF) is pleased to announce 24 new Young Investigator (YI) ... of the Class of 2016 were selected from a pool of 128 applicants ... the Class of 2016 PCF Young Investigators ... ... ...
(Date:6/23/2016)... ... June 23, 2016 , ... STACS DNA Inc., the sample tracking software company, ... Crime Laboratory, has joined STACS DNA as a Field Application Specialist. , “I ... President and COO of STACS DNA. “In further expanding our capacity as a scientific ...
(Date:6/23/2016)... -- Andrew D Zelenetz , ... Published recently in Oncology & ... Andrew D Zelenetz , discusses the fact ... placing an increasing burden on healthcare systems worldwide, ... the patents on many biologics expiring, interest in ...
(Date:6/23/2016)... Connecticut (PRWEB) , ... June 23, 2016 , ... ... introduce a new line of intelligent tools designed, tuned and optimized exclusively for ... September 12–17 in Chicago. The result of a collaboration among several companies with ...
Breaking Biology Technology: