If Darwinian Evolution Can’t Fix Broken Genes, How Can It Create New Ones?
|August 30, 2010||Posted by Jonathan M under Intelligent Design|
The Darwinian model of evolution holds that one of the key mechanisms of evolutionary innovation is the duplication of genes and the subsequent divergence of one of the duplicate copies to undertake a new functional role. Because a probability of a single gene stumbling upon a significantly different (yet functionally advantageous) sequence is so small, the idea is that, following a duplication of a gene, one copy is able to retain the original function, while the other is free to explore the vast sea of combinatorial possibilities in search of some novel function. It is widely believed that a duplicate gene has no phenotypic cost or advantage associated with it – that is, it is selectively neutral. In such a state, it is thought that the gene is free to mutate, independent of selection constraints or pressure. When a previously protein-coding gene incurs deleterious mutations such that it no longer codes for a useful polypeptide, the gene is rendered a “pseudogene”. One recent paper, which recently appeared in the open-access journal, PLoS Genetics, by Kuo and Ochman, entitled “The Extinction Dynamics of Bacterial Pseudogenes”, offers a potent challenge to this view. According to the paper’s abstract: Read more >>