Navigation Links
Dawn of human matrilineal diversity
Date:4/24/2008

WASHINGTON, DC (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.


'/>"/>

Contact: Glynnis Breen
gbreen@ngs.org
202-857-7481
National Geographic Society
Source:Eurekalert

Related biology news :

1. Bloodless worm sheds light on human blood, iron deficiency
2. Are humans hardwired for fairness?
3. Human vascular system in mice
4. Scientists find a fingerprint of evolution across the human genome
5. Technique traces origins of disease genes in mixed human populations
6. Reflecting on the social implications of human genetics research -- past, present and future
7. A call to infuse scientific knowledge into the human experience
8. A new method to identify mutated genes in human diseases
9. Long-term use of mechanical ventilation contributes to the deterioration of human diaphragm muscle
10. Scientists launch first comprehensive database of human oral microbiome
11. Scientists launch human oral microbiome database
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:4/13/2017)... 13, 2017 According to a new market research ... Analytics, Identity Administration, and Authorization), Service, Authentication Type, Deployment Mode, Vertical, and ... is expected to grow from USD 14.30 Billion in 2017 to USD ... 17.3%. ... MarketsandMarkets Logo ...
(Date:4/6/2017)... Forecasts by Product Type (EAC), ... End-Use (Transportation & Logistics, Government & Public Sector, Utilities ... Generation Facility, Nuclear Power), Industrial, Retail, Business Organisation (BFSI), ... you looking for a definitive report on the $27.9bn ... ...
(Date:4/3/2017)...  Data captured by IsoCode, IsoPlexis Corporation,s ... statistically significant association between the potency of ... objective response of cancer patients post-treatment. The ... cancer patients will respond to CAR-T cell ... to improve both pre-infusion potency testing and cell ...
Breaking Biology News(10 mins):
(Date:6/22/2017)... , ... June 22, 2017 , ... ... leaders in designating infertility as a disease, bringing new hope for prospective parents ... their 2017 annual meeting to back the World Health Organization’s designation in hopes ...
(Date:6/22/2017)... ... June 22, 2017 , ... Tunnell ... the biopharma and life sciences industries, continue to be in demand for their ... Wolf will be speaking on “The State of Information Governance in the Biopharmaceutical ...
(Date:6/22/2017)... ... June 22, 2017 , ... RURO, Inc., ... Limfinity® version 6.5, a content-packed update to the Limfinity® framework. , LimitLIS® and ... and more diverse base of customers among labs and other businesses. Limfinity® 6.5 ...
(Date:6/20/2017)... ... June 20, 2017 , ... ... CTNext board of directors has formed a Higher Education Entrepreneurship Advisory Committee to ... of institution presidents and other high-ranking representatives from 35 higher education institutions across ...
Breaking Biology Technology: