A Stomach Bacteria Offers Clues on Human Migration
Ötzi the Iceman was a dapper dresser. About 5,300 years ago, he sported a fur hat made from a brown bear, a sheepskin loincloth, leggings and a coat made of goat hide, shoelaces from wild cows, and a quiver made from deer leather.
An insight into the peopling of Europe has emerged from an unlikely source — the stomach contents of a 5,300-year-old body pulled from a thawing glacier in the eastern Italian Alps.
Since his discovery in 1991, Ötzi the Iceman, as he was named, has provided a trove of information about the life of Europeans at that time. His long-frozen tissues have now yielded another surprise: Scientists have been able to recover from his stomach samples of Helicobacter pylori, a bacterium that infects about half the human population and can occasionally cause stomach ulcers.
The bacterium is transmitted only through intimate contact, and its distribution around the world matches almost perfectly the distribution of human populations. The bacterium’s genetic variations are therefore used by researchers as a supplement to human genetics in tracking ancient human migrations.
Researchers led by Frank Maixner and Albert Zink of the Institute for Mummies and the Iceman, at the European Research Academy in Bolzano, Italy, reported on Thursday in Science that they had been able to reconstruct the entire DNA sequence of the ulcer bacterium from samples taken from the iceman’s stomach.
Modern-day Europeans carry a type of H. pylori that is a hybrid of two ancient strains, one of which originated somewhere in Eurasia and the other in Africa, after modern humans first left that continent about 50,000 years ago.
One theory is that this hybridization occurred in the Middle East before or during the Last Glacial Maximum, a catastrophically cold period during the last ice age when glaciers swept south and made much of Europe uninhabitable.
Source: New York Time/Science
Wowza, problem solved like it never haeppned.
Trả lờiXóaA musica original deste video se chamaCorner of the earth,,o artista que aparece na tela do video se chama Jamiroquai,mas veja bem,a musica do video não não é Corner of the earth.
Trả lờiXóaDoucement mais sûrement ! Une refonte de l’EN ne peut se faire que dans la concertation. Fini les décisions unilatérales et à l’emporte-pièce ! On bosse, c’est tout !
Trả lờiXóa