Sydney (AFP) – A petition demanding an inquiry into Rupert Murdoch’s dominance of Australian news media has garnered a record 420,000 signatures, overtaking a previous appeal focused on climate change.The online petition was launched on October 12 by former Labor prime minister Kevin Rudd, a frequent target of newspapers controlled by Murdoch’s News Corp.By Friday, the call for a Royal Commission of inquiry into the impact of the group on media diversity had been signed 420,695 times on the national parliament’s e-petition web page.That eclipsed the previous record for an e-petition of 404,538…