Mutation repairing plant defies evolutionary genetics, according to reports in news@nature and ScienceNOW, 23 Mar 2005. Susan Lolle and Robert Pruitt of Purdue University, Indiana have been studying a mutant plant gene called HOTHEAD which prevents cress plant flowers from opening properly. Plants with two copies of this gene have their floral parts stuck together in little balls. The deformed flowers can self-fertilise, which means offspring therefore can only inherit two copies of the mutant gene, so they should have deformed flowers as well. However, Lolle and Pruit found that up to ten percent of such offspring have normal flowers. This is only possible if one of the mutant genes has been replaced by a normal gene. But according to accepted laws of genetics, this could not happen because parent plants only had mutant genes to give to offspring.
When researchers sequenced the gene in the second generation plants which had the unexpected normal flowers (i.e. read its genetic code letters), they found the newly normal plants had indeed replaced the mutated genetic code with the normal code. The scientists then studied other mutant genes and found some of the plants were also able to return these to ancestral normal forms as well. The only way plants could have done this is if they had some kind of back-up copy of the normal gene to check the mutation against. However, the plants have not been found to have a back-up copy in their DNA, so the source of the back-up copy is still undiscovered. Some scientists suggest it may be RNA, which could passed into pollen or seeds.
Editorial Comment: The more we study processes involved in storing and passing on genetic information, the more evidence we find genes are designed not to evolve. (The ScienceNOW article was entitled “Evolution in Reverse”)
Whatever method these cress plants use to repair broken DNA it makes evolution by mutation a whole lot harder, and reproduction “after their kind’ more certain. It is possible that in the original good world God made, all living organisms had such a back-up system fully functional so that any mutations were repaired within one generation, and therefore never accumulated across generations, but as the world degenerated after the fall and after Noah’s flood, this back-up system it gradually degenerated and now only works in a small percentage of cells. It makes devolution possible, but not evolution. (Ref Creation, Genesis Kinds, Degeneration)