Navigation Links
Out of Africa -- Bacteria, as well

When man made his way out of Africa some 60,000 years ago to populate the world, he was not alone: He was accompanied by the bacterium Helicobacter pylori, which causes gastritis in many people today. Together, man and the bacterium spread throughout the entire world. This is the conclusion reached by an international team of scientists led by Mark Achtman from the Max Planck Institute for Infection Biology in Berlin, Germany. The researchers also discovered that differences developed in the genetic makeup of the bacteria populations, just as it did in that of the various peoples of the world. This has also given scientists new insight into the paths taken by man as he journeyed across the Earth (Nature online, February 7, 2007).

More than half of all human beings are infected with Helicobacter pylori, a bacterium that can cause stomach ulcers. Like humans, the bacteria are also split up into numerous regional populations. A team of scientists led by Mark Achtman at the Max Planck Institute for Infection Biology, François Balloux at the University of Cambridge and Sebastian Suerbaum at Hanover Medical University have found signs of the parallel evolution of man and H. pylori. Using mathematical simulations, the researchers demonstrated that H. pylori must have left East Africa at the same time as man - around 60,000 years ago. This astonishing conformity was uncovered by scientists when they compared the nucleotide sequencing patterns in the DNA of human and H. pylori populations.

In order to characterise the individual populations, the scientists employed the principle of isolation by distance. According to this principle, the genetic distance between two populations has a linear correlation with the length of the migration paths taken since they were separated. "It's actually quite logical," explains Dr. Mark Achtman, "because in the time that elapses after a population leaves its point of origin, the number of mutations in its genetic makeup continually increases."

However, while man was spreading throughout the world, human populations had to repeatedly pass through what scientists call genetic bottlenecks: when a population shrinks, the gene pool also becomes smaller. These losses in genetic diversity linger, even when the population starts once again to increase in number. Since the Homo sapiens populations usually had to pass through several genetic bottlenecks on their way across the globe, their genetic diversity declined the further they journeyed from their origin in East Africa.

Scientists have now uncovered similar signs of historical population migration in the genetic makeup of H. pylori. However, the genetic diversity of the bacteria is larger than that of man. This paves the way for researchers to use H. pylori data to work out the migratory movements of modern man. "The parallels between the spread of man and of H. pylori are truly astonishing," says Achtman. "This bacterium could help us attain further information on aspects of human history that are still hotly disputed today if we analyzed H. pylori in conjunction with human data." For example, after leaving East Africa, the H. pylori population spread through limited localities in southern Africa, West Africa, Northeast Africa, India and East Asia. The genes of bacteria isolated in Europe, for instance, reveal influences from Central Asia - an indication that human immigrants came to Europe from Asia.


'"/>

Source:Max-Planck-Gesellschaft


Related biology news :

1. New push for public health, AIDS spending at African Union summit
2. A comprehensive response to HIV could prevent 10 million AIDS deaths in Africa by 2020
3. Scientists discuss improved biopesticides for locust control in West Africa
4. Reducing malarial transmission in Africa
5. Scientists journey to southern Africa to unravel the secret world of elephant communication
6. Africa to take it on chin again with climate change
7. Study reveals dramatic difference between breast cancers in US and Africa
8. South African Tribunal Asks For Damages Estimates in GSK AIDS Drug Case
9. Researchers find new giant amphibian fossils in Africa
10. A New Species of Monkey is Discovered in Tanzania: The First in Africa for More Than 20 Years
11. Six million Africans face famine because of locusts, drought
Post Your Comments:
*Name:
*Comment:
*Email:


(Date:3/23/2017)... March 23, 2017 The report "Gesture Recognition and Touchless ... and Geography - Global Forecast to 2022", published by MarketsandMarkets, the market is ... of 29.63% between 2017 and 2022. Continue Reading ... ... ...
(Date:3/20/2017)... 20, 2017 At this year,s CeBIT Chancellor Dr. ... manufacturer DERMALOG. The Chancellor came to the DERMALOG stand together with the ... year,s CeBIT partner country. At the largest German biometrics company the two ... face and iris recognition as well as DERMALOG´s multi-biometrics system.   ... ...
(Date:3/9/2017)... and MOUNTAIN VIEW, Calif. , March ... Made Simple," and 23andMe , the leading personal ... food choices.  Zipongo can now provide customers with personalized ... health goals and biometrics, but also genetic markers impacting ... Zipongo,s personalized food decision support platform uses ...
Breaking Biology News(10 mins):
(Date:3/23/2017)... York , March 23, 2017 According ... plasma products and derivatives market is fragmented due to the presence of ... such as Proliant, Thermo Fisher , and Sigma-Aldrich, compete with ... these three companies, collectively, held more than 76% of this market ... As ...
(Date:3/23/2017)... In today,s pre-market research, Stock-Callers.com ... Biotech industry: Sangamo Therapeutics Inc. (NASDAQ: SGMO), Eyegate Pharmaceuticals ... and Regulus Therapeutics Inc. (NASDAQ: RGLS ). ... its rating on Pharmaceuticals/Biotechnology to "Overweight" from "Market Weight." Learn more ... ...
(Date:3/22/2017)... TARRYTOWN, N.Y. , March 22, 2017 Regeneron ... among the Regeneron Genetics Center (RGC), U.K. Biobank and GSK ... in the U.K. Biobank resource. The initiative will enable researchers ... of new medicines for a wide range of serious and ... ...
(Date:3/22/2017)... COPENHAGEN, Denmark , March 22, 2017 /PRNewswire/ ... that utilizes its innovative TransCon technology to address ... announced financial results for the full year ended ... a significant year for our company as we ... become a leading, integrated rare disease company with ...
Breaking Biology Technology: