Posted on 01/21/2015 6:34:38 AM PST by SunkenCiv
Although M. tuberculosis probably first emerged some 40,000 years ago in Africa, the disease did not take hold until humans took to farming... A previous analysis by his team had shown that the common ancestor of all the M. bacterium strains circulating today began spreading around 10,000 years ago in the ancient Fertile Crescent, a region stretching from Mesopotamia to the Nile Delta that was a cradle of agriculture... 4,987 samples of the Beijing lineage from 99 countries... the information to date the expansion of the lineage and show how the strains are related... the Beijing lineage did indeed emerge near north-eastern China... around 6,600 years ago, the researchers found, which coincides with archaeological evidence for the beginnings of rice farming in China's upper Yangtze River valley.
Travel along the Silk Road, which connected China with the Middle East, probably helped to spread the lineage beyond East Asia, the researchers say...
Anne Stone, an evolutionary geneticist at Arizona State University in Tempe, is impressed by the number of samples that Wirth's team examined. The 6,600-year date that the team calculated for the emergence of the Beijing lineage clashes with an estimate that she and her colleagues published last year, which put the emergence at around 1,200–2,400 years ago. That study was based on TB genomes collected from 1,000-year-old Peruvian mummies and used different dating methods. But Stone now wonders if her team's estimate is on the young side. "Looking at this study, I'm thinking 'hmm we should play with this data set'," she says.
(Excerpt) Read more at nature.com ...
thousands, not millions
A few important notes:
Farming provided enough food so that people *could* live together. But agricultural animals also act as vectors of the disease. Cattle, pigs, African buffalo (not domesticated), hippopotamus, cats and rodents.
Importantly, there are a bunch of different kinds of TB, only some of which infect humans. But this bacterial specialization could have happened at any point in history.
Thanks yefragetuwrabrumuy.
It started 6,600 years ago in China, but didn’t show up in Peru until 2,000 years ago and this is a clash/surprise? Does this scientist think there was airplane and steamship travel 6,000 years ago. Time line of 4,000+ years to get from China to Peru sounds about right for that period.
Not from Europeans.
YA...I have one of his old CD’s.
This topic was posted , re-ping.
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