Meet Your Microbiome
Meet Your Microbiome
Humans are sometimes held up as the ultimate example of the ability to transfer information from one generation to the next, through the use of language and culture. However, bacteria can be regarded as equally adept at social learning. They transfer genes with massive frequency, so that in some species only about 40% of the genome is common to all individuals. Ulvestad likens their uptake of ready-made genes from a mobile gene pool to the rapid uptake of new ideas by humans of information from the internet. This can be to the disadvantage of humans—for instance, in the way that Neisseria gonorrhoeae has developed resistance to all known drugs. It can also benefit us. One example is the way that Japanese people who regularly eat seaweed can digest the polysaccharide porphyran because the bacteria on seaweed can transfer the gene for the appropriate enzyme to human intestinal flora. Bacteria also indulge in what Ulvestad calls 'cross-talk': they release and sense diffusible molecules that allow them to respond collectively to the environment in a coordinated manner—for example, by manufacturing biofilms to defend against antibiotics. They often do so by 'quorum sensing', which enables them to know when their numbers are sufficient for such collaborative projects to be feasible.
One of Ulvestad's missions is to try to help everyone move away from the 'war' metaphor when talking about micro-organisms. This pervasive metaphor in medicine arose in the nineteenth century, largely because most researchers were doctors, and they focused almost exclusively on pathogens. He reminds us that at least one of the great early immunologists—the Russian, Ilya Mechnikov—was more concerned with studying how competition and co-operation were finely balanced in biology. More than a century after Mechnikov, this perspective has become almost universal in evolutionary and biological studies. A modern evolutionary view does not see any organisms—from viruses to humans—as intrinsically good or bad, but applies scientific curiosity in order to establish how hosts and infectious agents negotiate relationships along a scale from lethal hostility to symbiotic harmony. Ulvestad writes: 'As scientists, we need to acknowledge the fact that we are only studying a brief interlude of biological time, which represents the current trade-offs reached by contemporary organisms subject to a number of evolutionary forces… These forces are still acting to diversify and complicate the biological processes, and the results of the trade-offs reached will be the challenges encountered by future scientists'.
Social Learning
Humans are sometimes held up as the ultimate example of the ability to transfer information from one generation to the next, through the use of language and culture. However, bacteria can be regarded as equally adept at social learning. They transfer genes with massive frequency, so that in some species only about 40% of the genome is common to all individuals. Ulvestad likens their uptake of ready-made genes from a mobile gene pool to the rapid uptake of new ideas by humans of information from the internet. This can be to the disadvantage of humans—for instance, in the way that Neisseria gonorrhoeae has developed resistance to all known drugs. It can also benefit us. One example is the way that Japanese people who regularly eat seaweed can digest the polysaccharide porphyran because the bacteria on seaweed can transfer the gene for the appropriate enzyme to human intestinal flora. Bacteria also indulge in what Ulvestad calls 'cross-talk': they release and sense diffusible molecules that allow them to respond collectively to the environment in a coordinated manner—for example, by manufacturing biofilms to defend against antibiotics. They often do so by 'quorum sensing', which enables them to know when their numbers are sufficient for such collaborative projects to be feasible.
One of Ulvestad's missions is to try to help everyone move away from the 'war' metaphor when talking about micro-organisms. This pervasive metaphor in medicine arose in the nineteenth century, largely because most researchers were doctors, and they focused almost exclusively on pathogens. He reminds us that at least one of the great early immunologists—the Russian, Ilya Mechnikov—was more concerned with studying how competition and co-operation were finely balanced in biology. More than a century after Mechnikov, this perspective has become almost universal in evolutionary and biological studies. A modern evolutionary view does not see any organisms—from viruses to humans—as intrinsically good or bad, but applies scientific curiosity in order to establish how hosts and infectious agents negotiate relationships along a scale from lethal hostility to symbiotic harmony. Ulvestad writes: 'As scientists, we need to acknowledge the fact that we are only studying a brief interlude of biological time, which represents the current trade-offs reached by contemporary organisms subject to a number of evolutionary forces… These forces are still acting to diversify and complicate the biological processes, and the results of the trade-offs reached will be the challenges encountered by future scientists'.
