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Natural Science Forum / Biology / Paleontology / February 2007Article: Prehistoric origins of stomach ulcers uncovered
Prehistoric origins of stomach ulcers uncovered An international team of scientists has discovered that the ubiquitous bacteria that causes most painful stomach ulcers has been present in the human digestive system since modern man migrated from Africa over 60,000 years ago. The research, published online today (7 February) by the journal Nature, not only furthers our understanding of a disease causing bacteria but also offers a new way to study the migration and diversification of early humans. The international research collaboration was led by scientists from the University of Cambridge, the Max Planck Institute in Berlin, and the Hanover Medical School. The researchers compared DNA sequence patterns of humans and the Helicobacter pylori bacteria now known to cause most stomach ulcers. They found that the genetic differences between human populations that arose as they dispersed from Eastern Africa over thousands of years are mirrored in H. pylori. Human DNA analysis has shown that along the major land routes out of Africa human populations become genetically isolated - the further from Eastern Africa a population is the more different genetically it is compared to other human populations. Other research has shown gradual differences in European populations, presumed to be the result of Neolithic farmers moving northwards. The international H. pylori research team found almost exactly the same genetic distribution patterns in their results. The scientists combined their genetic analysis with a computer simulation the modelled the spread of the bacteria across the globe. This showed that it migrated from Eastern Africa at almost exactly the same time as early humans, approximately 60,000 years ago. The UK research effort was led by Dr Francois Balloux, a Biotechnology and Biological Sciences Research Council-funded scientist at the University of Cambridge. He said: "Humans and this ulcer-causing bacterium have been intimately linked for the last 60,000 years. The research not only shows the likelihood that for tens of thousands of years our ancestors have been suffering the effects of this bacteria but it also opens up new possibilities for understanding early human migration. By showing that Helicobacter pylori emerged from Africa at the same time as early humans it makes it easier to examine some of the controversial questions about human migration. For example we could use our understanding of the bacteria's spread to gauge poorly understood human population shifts in Europe, Africa and Asia." Source: Biotechnology and Biological Sciences Research Council http://www.eurekalert.org/pub_releases/2007-02/babs-poo020507.php Posted by Robert Karl Stonjek > Prehistoric origins of stomach ulcers uncovered > An international team of scientists has discovered that the ubiquitous bacteria > that causes most painful stomach ulcers has been present in the human > digestive system since modern man migrated from Africa over 60,000 years ago. The bacteria had probably been present in the gut for a long time before that. > The research, published online today (7 February) by the journal Nature, not > only furthers our understanding of a disease causing bacteria but also offers > a new way to study the migration and diversification of early humans. Another interesting aspect is that it indicates that friendly contact between hominid populations was always minimal. It strongly suggests that there was very little friendly contact between H.sap and all other hominids, not just during the migration and expansion of H.sap, but between their ancestors during the millions of years up to 60 kya. If there had been such contact, then the varieties of H.pylori among different hominids would have intermingled, Paul. >> Prehistoric origins of stomach ulcers uncovered >> An international team of scientists has discovered that the ubiquitous [quoted text clipped - 25 lines] > of H.pylori among different hominids would have > intermingled, Does it use sexual reproduction? Just asking. > Paul. >>> Prehistoric origins of stomach ulcers uncovered >>> An international team of scientists has discovered that the ubiquitous [quoted text clipped - 27 lines] >> > Does it use sexual reproduction? Just asking. Standard asexual reproduction. Jois >>>> Prehistoric origins of stomach ulcers uncovered >>>> An international team of scientists has discovered that the ubiquitous [quoted text clipped - 30 lines] > Standard asexual reproduction. > Jois Then I would expect one line or the other to take over. >>>>> Prehistoric origins of stomach ulcers uncovered >>>>> An international team of scientists has discovered that the ubiquitous [quoted text clipped - 32 lines] > > Then I would expect one line or the other to take over. Isn't that also what you'd expect with sexual reproduction just by chance? mtDNA lines drop out of sight and some last names disappear over time. Jois >>>>>> Prehistoric origins of stomach ulcers uncovered >>>>>> An international team of scientists has discovered that the [quoted text clipped - 34 lines] > Isn't that also what you'd expect with sexual reproduction just by chance? > mtDNA lines drop out of sight and some last names disappear over time. Wouldn't surprise me but the poster had said that the lack of mixing meant no Asian genus Homo genes made it. The organism is asexual so no mixing would be apt to occur and only one population would be expected to be around. Of course we already know some Asian genes made it. Not a big percentage but some. > Jois >>>> Standard asexual reproduction. >>>> Jois [quoted text clipped - 6 lines] > genes made it. The organism is asexual so no mixing would be apt to occur and only one > population would be expected to be around. I'm know nothing about the evolution of bacteria, but I'd expect some intermingling (somehow) of genes, if separate populations of the same species came into contact. I fully accept that I could be quite wrong. The original report stated: >|>|> They found that the genetic differences between human |>|> populations that arose as they >dispersed from Eastern Africa |>|> over thousands of years are mirrored in H. pylori. I'd bet that the same pattern is NOT reflected in those human parasites that don't need close contact between populations of the host species, such as fleas, tapeworms, bed-bugs or bilharzia. Our ancestors would have 'inherited' the local bugs from the local population of hominids when they moved in -- and vice versa. Paul. In sci.anthropology.paleo, on Fri, 16 Feb 2007 12:19:43 -0000, Paul Crowley <slkwuoiutiuytciuyik@slkjlskjoioue.com> sez: >>>>> Standard asexual reproduction. >>>>> Jois >>>> >>>> Then I would expect one line or the other to take over. >>> Isn't that also what you'd expect with sexual reproduction just by >>> chance? mtDNA lines drop out of sight and some last names disappear >>> over time. >> Wouldn't surprise me but the poster had said that the lack of mixing >> meant no Asian genus Homo genes made it. The organism is asexual so no >> mixing would be apt to occur and only one population would be expected >> to be around. >I'm know nothing about the evolution of >bacteria, but I'd expect some intermingling >(somehow) of genes, if separate populations >of the same species came into contact. >I fully accept that I could be quite wrong. >The original report stated: >> |>|> They found that the genetic differences between human |>|> populations that arose as they dispersed from Eastern Africa |>|> over thousands of years are mirrored in H. pylori. >I'd bet that the same pattern is NOT reflected >in those human parasites that don't need close [quoted text clipped - 3 lines] >bugs from the local population of hominids >when they moved in -- and vice versa. http://en.wikipedia.org/wiki/Bacterial_conjugation ...says it's "rare" in bacteria. However, note here: http://www.pubmedcentral.nih.gov/botrender.fcgi?blobtype=html&artid=107256 Bingo.  Signature========================================================================== vincent@triumf[munge].ca Pete Vincent Disclaimer: all I know I learned from reading Usenet. > In sci.anthropology.paleo, on Fri, 16 Feb 2007 12:19:43 -0000, > Paul Crowley <slkwuoiutiuytciuyik@slkjlskjoioue.com> sez: [quoted text clipped - 42 lines] > > Bingo. Some refs Feldgarden, Michael, Noah Byrd, and Frederick M. Cohan (2003), "Gradual evolution in bacteria: evidence from Bacillus systematics", Microbiology 149 (12):3565-3573. Werren, J. H., and J. D. Bartos (2001), "Recombination in Wolbachia", Curr Biol 11 (6):431-435. Koonin, E. V., K. S. Makarova, and L. Aravind (2001), "Horizontal gene transfer in prokaryotes: quantification and classification", Annu Rev Microbiol 55:709-742. Lawrence, Jeffrey G. (2001), "Catalyzing Bacterial Speciation: Correlating Lateral Transfer with Genetic Headroom", Sys t. Biol. 50 (4):479-496. SignatureJohn S. Wilkins, Postdoctoral Research Fellow, Biohumanities Project University of Queensland - Blog: scienceblogs.com/evolvingthoughts "He used... sarcasm. He knew all the tricks, dramatic irony, metaphor, bathos, puns, parody, litotes and... satire. He was vicious." > In sci.anthropology.paleo, on Fri, 16 Feb 2007 12:19:43 -0000, > Paul Crowley <slkwuoiutiuytciuyik@slkjlskjoioue.com> sez: [quoted text clipped - 44 lines] > > -- I asked if these strains used sexual reproduction and got no. Conjugation is the norm among microbes that use sexual reproduction or at least it was back when I took biology in college. If these microbes use conjugation the answer should have been yes. Other methods for moving around DNA do exist but... Don't count on them. It is pretty hit or miss. Something might get moved right away or not. Viruses do move material. Consumption does move material and the article suggests that free DNA may be taken in. In any event according to the article DNA exchange could have occurred because it has been demonstrated under lab conditions. No evidence for such exchange has been reported in this instance. > ========================================================================== > vincent@triumf[munge].ca Pete Vincent > Disclaimer: all I know I learned from reading Usenet. "This showed that it migrated from Eastern Africa at almost exactly the same time as early humans, approximately 60,000 years ago. " No, it shows that it migrated TO Eastern Africa...."". If it had migrated from Eastern Africa, then it would have been in the African ancestral population earlier. Since it wasn't found in Norht, West, South Africans of earlier pops. it must have arrived there and then spread. Most likely due to Mt Toba 73.5ka moving people around. |
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