“Ultraconserved DNA” … Another Failed Prediction of Evolution
Nature 449, 1 (6 September 2007) | doi:10.1038/449001a
Life as we know it
The paper in question focuses on segments of ‘ultraconserved’ DNA — sections that have stayed exactly the same throughout recent vertebrate evolution, and are identical in humans, rats and mice (see page 10). The available evidence suggests that this extreme example of DNA conservation is no accident: the sequence stays because there is a strong selective force weeding out mutations in it. In other words, it is likely to be important to its host.
Yet when researchers based at Lawrence Berkeley National Laboratory in California removed four pieces of ultraconserved DNA from different mice, it had absolutely no effect on the rodents (N. Ahituv et al. PLoS Biol. 5, e234; 2007). This counterintuitive result contradicts predictions based on genetic conservation and the shaping of our genomes during evolution. http://www.nature.com/nature/journal/v449/n7158/full/449001a.html (Picture credit: Wikipedia “DNA”)