The vast majority of the human genome consists of DNA without any apparent function, so-called “junk DNA”. A study conducted by the scientists Dr. Laurence Ettwiller and Michael Eichenlaub at Heidelberg University’s Centre for Organismal Studies now highlights this “dark matter” of the genome as a resource for evolutionary novelty. The scientists found that even small changes in functionally inactive “junk DNA“ are sufficient to create essential control elements in gene regulation known as enhancers. The results of the study will be published on 1 November 2011 in “PLoS Biology”.
Genetic variation in humans is not primarily due to differences in the 1.5 percent of DNA that code for gene products. Rather, experts today assume that most differences between humans are the result of changes in those DNA sequences that control gene regulation, i.e. the formation of gene products such as proteins. Enhancers are an essential component in the control mechanism of gene regulation. Changes in enhancers can lead to disease and malformation; on the other hand, they carry the potential for evolutionary innovation.