Short Dog Leg Gene

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Short dog leg gene found, according to articles in National Institutes of Health News 16 July 2009 and ScienceDaily 17 July 2009 and Science, vol. 325, p995, 21 August 2009 (originally published in Science Express on 16 July 2009). An international team of scientists have found the gene that gives dog breeds such as dachshund, corgi, Pekingese and basset hound their distinctive short stubby legs. All these breeds have an extra copy of a gene that codes for a protein named fibroblast growth factor 4 (fgf4) . The extra gene results in an overproduction of a protein, and the researchers suggest this turns on growth receptors at the wrong times during growth and development of the bones, resulting in a deformity of the limb bones called chondrodysplasia.

The presence of chondrodysplasia is part of the breed standard defining 19 short legged breeds including dachshund, corgi, and basset hound. The researchers suggest the extra gene is a retrogene – a gene acquired when the RNA copy of the original gene is converted into another strand of DNA, which is then inserted into another place in the genome. This can occur when a type of virus called a retrovirus is present in a cell. The copied gene is not always functional, and even when it is it is not under the same controls as the original gene as it is in a different part of the genome to the original.

Because all the short legged breeds were found to have the extra fgf4 gene the researchers concluded that the formation of the retrogene was a “single evolutionary event” that occurred sometime after the ancestor of modern dog breeds diverged from wolves. One of the researchers, Heidi G. Parker of National Human Genome Research Institute (NHGRI), Bethesda, USA, commented: "Our findings suggest that retrogenes may play a larger role in evolution than has been previously thought, especially as a source of diversity within species. We were surprised to find that just one retrogene inserted at one point during the evolution of a species could yield such a dramatic physical trait that has been conserved over time."

The researchers hope their finding will help medical scientists looking for causes of similar bone deformities in humans. NHGRI Scientific Director Eric Green commented: "Every species, including canine and human, carries an amazing record of evolution scripted in its genome that can teach us about the mechanisms at work in biology, as well as about human health and disease. This work provides surprising evidence of a new way in which genome evolution may serve to generate diversity within a species."

NIH, ScienceDaily

Editorial Comment: The interpretation of these results is a classic example of using Darwin's Glasses , a term we have coined to describe the thought processes that define evolution as change, then call all change evolution, then accept any change as proof of evolution, then turn around and claim such change disproves creation.

If you are brave enough to take off Darwin's Glasses , you will see the genetic change described above is not evolution. It is a degenerative change that has interfered with a well functioning system for forming structurally sound dog legs, and has resulted in deformed limbs that would not have enabled to dogs to survive in the struggle for life if they were still living with the wolves. Short legged dogs have survived because human beings have deliberately selected them for this trait and cared for them.

Furthermore, the dogs are still the same species as any other domestic dog with normal legs. Once again we see that mutation and selection, the mechanisms claimed by evolutionists to produce new kinds of fitter organisms really only cause defective organisms of the same species. The findings in this study are actually good evidence that change is true, but it is not evolution. It is evidence that in the natural world, living things are going downhill from an original created perfection, just Genesis tells us. (Ref. canines, pedigrees, skeleton)

Evidence News, 19 November 2009

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