DARWINIAN SELECTION IN JAPANESE GUTS, according to articles in ScienceNOW 7 Apr 2010 and ABC (Australia) News in Science 8 April 2010. Mirjam Czjzek of Station Biologique de Roscoff, an offshore research facility in France has been studying a bacterium named Zobellia galactanivorans to find out how bacteria feed off seaweed. This bacterium has five genes for enzymes that can break down to the carbohydrates in seaweed. Czjzek and her colleagues then looked for genes for seaweed digestion in other bacteria. They found two genes in a number of other marine bacteria and, to their surprise, a bacterium named Bacteroides plebeius that has so far only been found in the intestines of Japanese people. Czjzek's team then compared the microbial genomes of 13 Japanese people with those of 18 North Americans. Five of the Japanese subjects had bacteria with a seaweed digesting enzyme, but none of the North Americans. Bacteria are known to be able to swap genes, so the scientist believe B. plebius picked up the genes from a bacterium living on seaweed that was ingested as part of the Japanese diet, e.g. sushi. Human digestive systems do not produce the enzymes that break down starches in seaweed. Czjzek suggested the seaweed digesting gut microbes might help Japanese who dine on seaweed get more nutrition from their meal than do North Americans. The ABC article explained: “In a classic example of Darwinian selection, strains of B. plebius that had the imported genes had a better chance of survival than others, as they could feast on a major component of the Japanese diet.”
ED. COM. This may be Darwinian selection, but it is not Darwinian evolution. The sushi digesting bacteria did not get the genes by evolution, but by a well known process of bacterial gene sharing. This is the same process that enables antibiotic resistance to spread so rapidly amongst bacteria, and seems to be a built-in process that enables bacteria to adapt to their environment. Whilst sharing antibiotic resistance genes is a bad thing for people suffering bacterial diseases and needing antibiotics, sharing digestive enzyme genes is a good thing for people who depend on a diet containing a lot of seaweed if it means they get more nutrients from their food. Human digestive systems do not produce enzymes that break down starches in seaweed. Therefore, people benefit from having bacteria that do this in their gut as the bacteria do not consume all the broken down starch. Recent studies on humans and bacteria have confirmed the importance of the symbiotic relationship we have with our gut bacteria in maintaining a healthy digestive system. Creation Research predicts that this process of gene swapping in the human gut, or any creature’s gut, will be found to be going on all the time to enable the bacteria to better carry out their symbiotic function to the benefit of the host also.
Again we remind people beware of the error Dawkins and most evolutionists make of assuming Natural Selection is evolution. Natural Selection is a real process, but it only acts on already existing organisms with already existing genes. (Ref. microbiology, algae, digestion)
Evidence News, 28 April 2010