Navigation Links
Long lost sisters
Date:5/15/2008

The human race was divided into two separate groups within Africa for as much as half of its existence, says a Tel Aviv University mathematician. Climate change, reduction in populations and harsh conditions may have caused and maintained the separation.

Dr. Saharon Rosset, from the School of Mathematical Sciences at Tel Aviv University, worked with team leader Doron Behar from the Rambam Medical Center to analyze African DNA. Their goal was to study obscure population patterns from hundreds of thousands of years ago.

Rosset, who crunched numbers and did the essential statistical analysis for the National Geographic Society's Genographic Project, said the team was trying to understand the timing and dynamics of the split into at least two separate groups.

We wanted to look into the ancient history of our species. How did we live throughout most of our existence as a species" Did we live as one or were we fractured into small groups" Until now, it wasnt really clear, says Rosset.

A Picture of the Ancient Past

Researchers believe that about 60,000 years ago, modern humans started their epic journeys to populate the world. This time period has been the primary focus of anthropological genetic research. However, 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 thereby refines the understanding of early modern Homo sapiens history.

Rosset, who is also affiliated with IBMs T.J. Watson Research Center in New York, says the study provides insight into the early demographic history of human populations before they moved out of Africa. These early human populations were small and isolated from each other for many tens of thousands of years, says Rosset.

The teams research was based on a survey of African mitochondrial DNA (mtDNA) and is the most extensive survey of its kind. It included over 600 complete mtDNA genomes from indigenous populations across the continent.

How Old Was Mitochondrial Eve"

MtDNA, inherited down the maternal line, was used in 1987 to discover the age of the famous Mitochondrial Eve, the most recent common female ancestor of everyone alive today. This work has since been extended to show unequivocally that Mitochondrial Eve was an African woman who lived sometime during the past 200,000 years.

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

Dr. Spencer Wells, director of the Genographic Project and Explorer-in-Residence at the National Geographic Society, said, "This new study 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."

Adds Rosset, Israelis and Jews are always curious about looking into their roots. Just in this study, we were digging deeper than we normally do.


'/>"/>

Contact: George Hunka
ghunka@aftau.org
212-742-9070
American Friends of Tel Aviv University
Source:Eurekalert  

Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Long lost sisters
(Date:6/20/2016)... -- Securus Technologies, a leading provider of civil ... investigation, corrections and monitoring announced that after exhaustive ... the final acceptance by all three (3) Department ... (MAS) installed. Furthermore, Securus will have contracts for ... October, 2016. MAS distinguishes between legitimate wireless device ...
(Date:6/9/2016)... -- Paris Police Prefecture ... to ensure the safety of people and operations in several ... tournament Teleste, an international technology group specialised in ... that its video security solution will be utilised by ... safety across the country. The system roll-out is scheduled for ...
(Date:6/2/2016)... June 2, 2016   The Weather Company , an ... Ads, an industry-first capability in which consumers will be able ... to ask questions via voice or text and receive relevant ... Marketers have long sought an advertising solution ... can be personal, relevant and valuable; and can scale across ...
Breaking Biology News(10 mins):
(Date:6/27/2016)... CA (PRWEB) , ... June 27, 2016 , ... ... for clinical trials, announced today the Clinical Reach Virtual Patient Encounter CONSULT ... care circle with the physician and clinical trial team. , Using the CONSULT module, ...
(Date:6/27/2016)... , June 27, 2016  Liquid Biotech ... the funding of a Sponsored Research Agreement with ... tumor cells (CTCs) from cancer patients.  The funding ... CTC levels correlate with clinical outcomes in cancer ... data will then be employed to support the ...
(Date:6/24/2016)... Epic Sciences unveiled a liquid biopsy ... PARP inhibitors by targeting homologous recombination deficiency (HRD) ... test has already been incorporated into numerous clinical ... Over 230 clinical trials are investigating ... PARP, ATM, ATR, DNA-PK and WEE-1. Drugs targeting ...
(Date:6/23/2016)... ... June 23, 2016 , ... ... of its second eBook, “Clinical Trials Patient Recruitment and Retention Tips.” Partnering with ... in this eBook by providing practical tips, tools, and strategies for clinical researchers. ...
Breaking Biology Technology: