Population genomics of degenerative genome evolution

点击翻译按钮获取中文摘要

One of the most striking features of genome evolution is found in cases of degenerative evolution, whereby large regions of the genome experience gene silencing and loss. Such genome degeneration is surprising, as it runs counter to the general prediction that natural selection should continually be driving genes towards improved function. Despite this, large-scale gene degeneration has occurred repeatedly, including recurrent degeneration of genes on non-recombining sex chromosomes, and loss of duplicate genes following whole genome duplication. The evolutionary forces driving degenerative evolution remain unclear; one possibility is that it may be driven by a 'passive' process of gene inactivation and loss through a reduction in the efficacy of natural selection. While reduced selection is likely important, the process of adaptation may also contribute: differences in fitness between derived gene copies may lead to adaptive gene inactivation and loss, accelerating degeneration.